Archinect - News

Foster + Partners reveals Seoul ‘live-work’ tower with bay window facade

2024-10-03T09:46:00-04:00

Foster + Partners has unveiled its design for a new high-rise “live-work” building in Seoul, South Korea. The 14-story building, on a corner plot in the city’s Dosan-daero Road, is intended to “cater for a highly personalized approach to business hospitality.”

Image credit: Foster + Partners

The scheme includes twelve whole-floor units with personalized spaces for working and entertaining as well as private rooms for relaxation. Each unit contains a personal vault and access to a luxury lounge area, where owners can securely view and display belongings to guests. The vaults also include private dining rooms, bars, and a wine cellar, while a wellness level on the floor below offers a spa, pool, and luxury treatment areas.

Image credit: Foster + Partners

Outside, the building’s street-facing facade is broken down into a series of bay windows with private green balconies and winter gardens. The penthouse unit also has access to a private roof terrace with views of the city.

Image credit:...

Heatherwick Studio proposes hourglass-shaped volumes for Seoul shopping center

2024-08-02T14:35:00-04:00

Another mixed-use retail project from Heatherwick Studio is coming to Seoul. The newly announced Hanwha Galleria project covers an existing metro subway station with a glass atrium and two landscaped plaza areas. Two asymmetrical glass volumes resembling hourglass forms and containing gardened areas conceal its program. According to the firm's project description, the structures come sheathed in a double-skinned facade that can be programmed for nighttime projections.

Neil Hubbard, partner and group leader at Heatherwick studio, described: "Traditionally, department stores are quite inward facing, they feel closed off to the surrounding streets. But here we have an important intersection in Apgujeong with two buildings, east and west, that felt like an opportunity to bring people together."

Local studio Haeahn Architecture will collaborate on its design.

Image: Devisual, courtesy Heatherwick Studio

The project’s announcement follows Thomas Heatherwick being named as General Director...

Kengo Kuma's new Seoul audio museum opens as an 'architectural instrument'

2024-07-10T14:37:00-04:00

Kengo Kuma and Associates has inaugurated what could be this year’s most interesting new cultural project, the new Audeum (or Audio Museum) in Seoul, South Korea, following a two-year construction period.

The world’s first museum experience dedicated to sound is approximately 2.4 million square feet and supports sensory healing while offering visitors a unique experience of both its architecture and exhibitions in a design that's meant to evoke the forest canopy surroundings it appears to be a metallic natural outgrowth of.

Image courtesy Namsun Lee

The design team describes it as a "place where you can not only see but also experience sound firsthand. [...] it is not just a place to listen to sound; it is an architectural instrument that returns humans to a natural state, allowing them to experience the five senses of the body."

Image courtesy Yongbaek Lee

Image courtesy Namsun Lee

The idea for its establishment can be credited to Korean acoustics equipment s...

Thomas Heatherwick to direct 2025 Seoul Biennale of Architecture and Urbanism

2024-06-03T19:10:00-04:00

South Korea's Seoul Biennale of Architecture and Urbanism just announced that Thomas Heatherwick will be the General Director of its fifth iteration next year.

Billed as Asia's biggest architecture biennial, the 2025 program seeks to explore "how to make buildings and cities radically more joyful and engaging," a mantra Heatherwick has been championing with his Humanise campaign.

"We are honored and thrilled by this appointment to curate our first Biennale," Heatherwick responded. "There are over 300 biennales taking place around the world today. But the original ambition to use them as vehicles for debate and engagement with the public, too easily gets lost in professional echo-chambers, which most ordinary people don’t engage with."

"We plan to turn the concept of a biennale inside out and create a big, full-throttle conversation with Seoulites. We want to get to the heart of what matter...

David Chipperfield’s K-Project corporate headquarters breaks ground in Seoul

2024-05-14T12:53:00-04:00

David Chipperfield Architects has just broken ground on a new corporate headquarters project for a South Korean IT company in Seoul. Construction for the new K-Project will advance toward a late 2027 completion and culminate in a new highly adaptable design that doubles as a piece of “social infrastructure” for the city’s Seongsu district.

Chipperfield says: “The energy and culture of the company occupying the building, and that of the diverse neighbourhood in which it is located are used to define a strong identity for the headquarters both visually through its dynamic façades and programmatically through a multi-use atrium.”

Rendering: Artefactory Lab, DCA, Brick

Programmatically, the concept works by traversing ‘Hardware’ and ‘Software’ layers vertically supported by eight vertical cylindrical cores, which lift the office component above a two-level ‘multiplex’ for retail and culture. This is the firm’s second corporate commission in Seoul after the completed Amorepacific Headqua...

Meier Partners completes Sorol Art Museum in South Korea

2024-01-30T18:43:00-05:00

Meier Partners has shared news of the recent completion of its Sorol Art Museum design in Gangneung, South Korea. The 336,500-square-foot project is meant to provide space for an immersive dialogue between Korean artists and the outside world and is the firm’s first completed work since its 2021 restructuring.

The building's internal structure is defined by a dual concept that arranges space into introverted and extroverted inter-dynamics based on the aesthetic theory of Korean Confucian philosophy. According to the architects, the external form utilizes the hillside’s natural topography to present the art inside on a pedestal to visitors in a way that also establishes the connection between nature and architecture as another core tenet of their experiences.

Image courtesy Meier Partners/Yongbaek Lee

Curators will have the option of controlling the gradations of light sources, both natural and artificial, inside the large skylit main exhibition space and smaller galleries. In a proj...

South Korea moves closer to getting its own MSG Sphere

2023-12-16T08:00:00-05:00

South Korean media outlets are reporting on a deal that would bring a new MSG Sphere design to the Seoul region just weeks after its controversial London predecessor was rejected over suspect environmental impact assessments and local opposition.

The new 20,000-capacity venue will feature a 1.2 million LED display, the same numbers as the now-open Las Vegas counterpart. The potential satellite would be included in the city of Hanam’s K-Star World project, a mixed-use district totaling 900,000 square meters and located roughly 12 miles to the east of the capital’s Gangnam neighborhood, according to the Korea Economic Daily.

"If Hanam attracts Asia’s first MSG Sphere, it will be an opportunity for Korea’s entertainment industry to take a quantum leap in attracting huge overseas investment and tourists," Mayor Lee Hyun-Jae told the paper in August.

He was reportedly looki...

RIOS unveils 100-year 'Hyper-Abundant City' concept at Seoul Biennale

2023-09-14T14:44:00-04:00

RIOS has released details of a new 100-year master plan included as part of its participation in the 4th Seoul Biennale of Architecture and Urbanism (SBAU), which takes place through the end of October in the South Korean capital.

The firm's concept for the 'Hyper-Abundant City' significantly alters the upscale Apgujeong district by incorporating the urban fabric of the adjacent Gangnam neighborhood while extending an existing connection to the Han River. Ecological plots revealing vertical villages that are inspired by Hanok architectural traditions are protected by shoreline islands which the architects say aid in managing stormwater runoffs and flood mitigation. Finally, the plots are connected to each other through an interlinking series of open spaces that permeate the site.

Rendering by Aesthetica Studio, image courtesy of RIOS

The river’s natural systems are relieved by the careful selection and placement of access points which minimize human activity while allowing land to...

Take a look inside Seoul's National Assembly Communication Building

2023-06-21T13:55:00-04:00

South Korean firm Haeahn Architecture, alongside New York-based H Architecture, has shared a video and photographs of their National Assembly Communication Building project in Seoul, South Korea.

The nearly 255,686-square-foot structure is located inside the National Assembly complex, the home of South Korea’s national legislature.

Image: Namsun Lee

The complex was planned as an open space that reflects a pluralistic ideology, while also staying in touch with the existing components of the site. To meet the needs of multiple user groups, the architects say the building’s design prioritizes flexibility and expandability.

Image: Namsun Lee

The project site was described as a green space surrounded by lush trees. The firms aimed to preserve this identity by making the building low and on a human scale, ensuring its height would not exceed four stories and be set amongst the trees. The rooftop also reflects these surroundings through the featured green zone.

Image: Namsun Lee

The archit...

Centre Pompidou is expanding to Seoul and Saudi Arabia

2023-03-28T11:44:00-04:00

The iconic Centre Pompidou has confirmed that it will open a branch in Seoul, South Korea. The new museum, set to open in 2025, will join the center’s existing network of outposts in Shanghai, Malaga, and the French city of Metz.

According to Artnews, the new museum will be housed in the headquarters of South Korean business conglomerate Hanwa Group, in a skyscraper known as 63 Square. French architect Jean-Michel Wilmotte is expected to oversee the design of the museum, having previously fulfilled interior design roles for the Louvre Museum and the British Museum.

When opened, the so-called “Pompidou Center Hanwha Seoul” will have permission to use the French museum’s properties for four years in a deal reported to be worth approximately 20 million USD. Throughout the four-year collaboration, the center will offer eight monographic exhibitions, spanning two per year, based on a selection of works from ...

Seoul wants to built a giant spokeless Ferris wheel by 2025

2023-03-20T12:05:00-04:00

South Korea’s capital has debuted an eye-catching new concept for the Seoul Ring, a new spokeless Ferris wheel it says will be the second largest in the world once it graces the city’s symbolic Haneul Park by the end of 2027.

The structure is reportedly meant to stimulate unity between North and South. The Seoul Metropolitan Government (SMG) says it will show “the harmony and reunification of the Korean race,” according to Hypebeast. Its ring will stretch to 590 feet, and it will be operated as a London Eye-type tourist attraction with a capacity for more than 11,000 passengers per day.

The Seoul Ring will be behind only the two-year-old Ain Dubai, which stands 820 feet, and will stand as the centerpiece of a cultural complex on the manmade Nodeul Island that was until recently a 30-acre landfill.

Image courtesy SMG

The SMC says it will be operated on renewables and be serviced by a fleet of all-electric transport vehicles. The Korean Herald reported costs to be around $310 million. ...

Herzog & de Meuron's exploration of the SongEun Art Space showcased possibilities of augmented reality technology

2022-03-18T14:31:00-04:00

Seoul’s latest cultural mainstay was a recent subject of an introspective investigation with help from its creator Herzog & de Meuron.

The Swiss firm returned to its debut Korean design with an augmented reality exhibition titled Exploring SongEun Art Space that uses physical and digital models, drawings, sections, and printed images to give visitors a real insider's perspective on the creation and inner workings of the new 11-story museum.

Previously on Archinect: Seoul's newest art space opens in a triangular concrete shape from Herzog & de Meuron

With help from Swiss VR/AR specialists Bandara, the installation delved into the new building in an extraordinary high-tech way, displaying documentation that explored the design and construction process from the initial conception in Basel to the physical realization last September in Seoul's Gangnam district. It consisted of seven augmented reality stations, where different images in the room triggered videos, models, and other media f...

UNStudio-designed K-Pop 'urban speaker' heralds an amplification of Seoul's music industry

2022-03-16T17:54:00-04:00

The urban environment of Seoul is about to get quite a bit visually louder as UNStudio has returned to the South Korean capital with a new headquarters for the expanding K-Pop label YG Entertainment.

The building is meant to encapsulate “the industrious spirit of this production house’s business and the music industry as a whole.”

Photo © Rohspace, courtesy UNStudio

Its sleek interior is a play on the ‘black in black’ concept inside the neighboring YG Building, offering a brightly-lit, tree-lined atrium with a host of white tones and geometric lines that improve wayfinding and are enhanced by an influx of natural sunlight directed through its roof.

Photo © Rohspace, courtesy UNStudio

Above the atrium, a sectional concept unfolds based on function starting with four stories of capsule-like collaborative spaces supporting several recording studios and seven additional floors of offices with a stage-like presence that...

Heatherwick Studio designs floating parkland pier for Seoul

2022-01-27T15:26:00-05:00

Heatherwick Studio has unveiled their proposal for a public waterfront development in Seoul, South Korea. The proposal forms part of a wider sports and cultural district close to the site of the 1988 Seoul Olympic Games.

Named The Leaf, the Heatherwick scheme consists of a multi-level pier sitting on the Han River. The pier features a walkable roofscape with undulating surfaces, consisting of winding trails, water gardens, play areas, observation points, and an event/auditorium space. The roofscape folds upwards at the edges to create lower-level waterside spaces as well as a marina for water taxis and leisure craft.

Image via Heatherwick Studio

“At the heart of our project is the idea of playful togetherness,” said Heatherwick Partner and Project Lead, Stuart Wood. “We want this to be a refreshing and dynamic new civic space for the city of Seoul where people come to laugh, explore, and connect. Somewhere joyful and restorative for everyone.”

Heatherwick is one of a number of arch...

Dominique Perrault on the role architects have in post-pandemic society

2021-11-09T11:48:00-05:00

In my opinion, many people consider architects less important today, while they demand engineers, landscape experts and environmentalists. It seems they no longer expect a comprehensive perspective and sensibility from architects. Architects should become advocates for architecture and fight for their role.

With the completion of the Seoul Biennale of Architecture and Urbanism 2021, Perrault will now pivot his focus to the 2024 Olympic Village plan that will help revitalize Saint-Denis, long-held to be one of the most neglected communes in the French capital region.

This year’s program focused on building resilience in cities as the specter of Covid loomed over the Biennale, causing disruptions in its traditional slate of in-person events. Perrault is currently finalizing plans for a new transit center in Seoul’s Gangnam district that will be completed in 2023.

Previously on Archinect: 2021 Seoul Biennale to open with online event on September 16th

“Going through the pandemic, it seems the proximity and heterogeneity of spaces have become important,” he said. “In order to keep up with the changing demand, new types of investment and a variety of projects are called for.”

The world's first K-Pop-dedicated concert venue breaks ground in South Korea

2021-11-04T17:06:00-04:00

South Korea is getting its first and largest-scale arena dedicated to K-Pop. The project, called CJ LiveCity Arena, is being spearheaded by CJ LiveCity, a subsidiary of South Korean entertainment company CJ ENM, in partnership with sports and live entertainment company AEG. The group held a groundbreaking ceremony last week to mark the start of the project’s construction phase. The arena is expected to open in 2024.

In a statement from 2019 announcing the partnership, CJ LiveCity’s CEO Michael Kim said: “This collaboration combines CJ’s long-standing cultural business capabilities with AEG’s venue development and operations expertise and its global live touring and promotions capacities. Seoul Metropolitan Arena, which will be designed by a leading architectural firm, is expected to be a competitive venue not only across Asia but also globally due to performances of K-Pop as well as world-renowned artists.”

The venue will be located in Greater Seoul’s Goyang City and is designed to ...

10-minute city masterplan for Seoul unveiled by UNStudio

2021-10-29T15:45:00-04:00

UNStudio has released details of Project H1, a self-described “10-minute city” masterplan for Seoul, South Korea. Built on an existing industrial site and railway area, the 5.4 million square foot (504,000 square meter) neighborhood saw a collaboration between UNStudio a the firm’s research wing UNSense to create a plan which prioritizes real-time digital urban systems.

Image courtesy of UNStudio

The studio describes this combination of a physical urban plan and an added technology layer as “a fully digitally serviced neighborhood to enhance the daily lives of the residents and free up time for leisure activities." The digital infrastructure will also be used to manage energy production and consumption, as well as communal spaces cultivated for local food production.

Image courtesy of UNStudio

“For the H1 masterplan we have aimed to create the ultimate contemporary 10-minute city, where the daily life experience of the residents is the top priority,” explained UNStudio founder Ben va...

Seoul's newest art space opens in a triangular concrete shape from Herzog & de Meuron

2021-07-15T14:04:00-04:00

A new home for South Korea’s energy giant ST International is nearing completion in Seoul, adding to the city’s reputation as an emerging art capital. The combination museum and corporate headquarters heralds a new vogue museum building in pronounced geometric form.

Herzog & de Meuron are behind the new SongEun Art Space that will double as an exhibition space for the 32-year-old foundation and the official home of the Korean conglomerate formerly known as Samtan. The Art Space has held dedicated space inside one of ST-owned properties since its inception in 2002.

The 8,000-square-meter new building forms a perfect right angle at the intersection of two busy main thoroughfares in Seoul’s Chung Dam district, its simple geometry serving as a complement to the optic new flagship for fashion house Juun.J that opened nearby in September 2019.

Wood-grained concrete forms an uneven 11-story scalene above-ground envelope that conceals the foundation’s subterranea...

Kohn Pedersen Fox shares images of newly completed Bundang Doosan Tower

2021-04-15T12:50:00-04:00

Kohn Pedersen Fox (KPF) recently completes the Bundang Doosan Tower in Jung District of central Seoul. With its stacked, interconnected masses, and glass facade what makes this tower so interesting is the 100-meter tall sky bridge connecting the two towers.

Designed for the Doosan Corporation James von Klemperer, KPF President and Design Principal explained, "The Bundang Doosan Tower represents the latest example of KPF’s work in Korea. The design strives for rational simplicity while being highly expressive and impactful. By using office building masses to define a large rectangular void, the composition affords striking views from the highway. The architecture conveys qualities of solidity and strength, and by organizing itself around a central space, it also communicates the value of community."

"In order to construct the skybridge, the 1,500-ton structure was preassembled on site at ground level and then lifted into place over the course of 24 hours." Image credit: Time of Blue...

What makes a city vertical?

2019-07-18T13:38:00-04:00

Which is the world's most vertical city? You might think of Hong Kong, given its famous skyscraper skyline, but by different measures of verticality other cities come out on top

"According to building data research company Emporis," writes Matthew Keegan for the Guardian Cities series, "Seoul in South Korea has more high-rise buildings, with 16,359. Emporis defines a high-rise as a building at least 35m, or 12 storeys tall. In second place is Moscow, Russia, with 12,317 high-rises, followed by Hong Kong in third place, with 7,913."

Robots will be in charge of the design, manufacturing, and construction of the upcoming Seoul Robot Science Museum

2019-02-21T12:36:00-05:00

Turkish based architecture studio Melike Altinisik Architects (MAA) wins the first ever international design competition hosted by The Seoul Metropolitan Government. The first competition of its kind, applicants were asked to submit a design idea to pioneer the world's first robot science museum. The technology for robots to design the built environment is not new to the architecture and design community. However, what makes this competition win so different is the level of autonomy the robots are given and robotic construction techniques used. According to MAA's principal Melike Altinisik, "the new robot science museum which plays a catalytic role in advancing and promoting science, technology, and innovation throughout society is not only going to exhibit robots but actually from design, manufacturing to construction and services robots will be in charge."

Robot Science Museum in Seoul, Korea. Design by MAA MELIKE ALTINISIK ARCHITECTS Visualization by Ediz Akyalçın

During the mus...

MVRDV completes a white and gold entertainment complex by Seoul’s Incheon Airport

2018-09-21T16:38:00-04:00

MVRDV has recently completed The Imprint, a new 2-building art and entertainment complex next to Seoul’s Incheon Airport. Featuring a nightclub in one building and indoor theme park in the other, the windowless structures are part of the larger Paradise City complex of 6 buildings next to South Korea's largest airport.

The program required an expressive facade with no windows. The firm created an imprint based design using façade features of the surrounding buildings, lifted entrances, and a golden entrance spot covering one corner of the nightclub building.

The façade was constructed of glass-fibre reinforced concrete panels. As many of the 3,869 panels are unique with construction requiring moulds to be individually produced using the f...

Seoul housing development builds traditional hanok designs for a slower lifestyle

2018-09-04T13:36:00-04:00

Eunpyeong Hanok Village was selling locals hanok, the traditional Korean tile-roofed residences that have, after hundreds of years, increasingly been destroyed and replaced by towering steel structures; indeed, not since the 1930s have hanok been constructed in significant numbers. The decline of vernacular architecture in the face of global urbanization is, of course, hardly new, though traditional Korean hanok are a particularly stark contrast to modern city living.

A new housing development, Eunpyeong, in northern Seoul is solely dedicated to constructing traditional Korean hanok houses. The design adheres to certain guidelines on proportion and design, with a low center of gravity, a courtyard, and an orientation towards nature.

The hanok's popularity comes from a need to connect to Korean identity and a desire to slow down from a past-paced economy. The minimalist design confronts the occupant with the amount of stuff they own and orients them to reconsider a new, slower way of life.

Morphosis announces opening of new flagship location for Kolon Group in Seoul

2018-08-28T16:12:00-04:00

Morphosis recently announced the opening of a new flagship research and design facility for The Kolon Group, a leading manufacturing company based in South Korea. The 820,000-square-foot facility is located in Magok, an emerging tech hub in Seoul.

Kolon Group facility by Morphosis, located in Seoul. Image: Jasmine Park, courtesy of Morphosis.

The design for the new facility features flexible laboratory facilities, administrative offices, and active social spaces to encourage interaction and exchange across the company departments.

Kolon Group facility by Morphosis, located in Seoul. Image: Jasmine Park, courtesy of Morphosis.

The façade consists of interconnected sunshades made from fiber reinforced polymer using one of The Kolon Group's own high-tech fabrics, Aramid, to increase the material’...

Seoul's first architecture biennale: "A kind of experimental laboratory of urban governance"

2017-11-02T13:52:00-04:00

From Zaha Hadid’s bulbous plaza to a ‘library’ of flora planted across a skygarden, the South Korean capital is using its architecture festival to look to the future – and atone for the costly sins of the past

The Guardian architecture critic Oliver Wainwright is in South Korea's capital reporting from the inaugural Seoul Biennale of Architecture and Urbanism. "There are over 200 biennales already, so we had to do something different," he quotes the event's curator Hyungmin Pai. "We see it as a kind of experimental laboratory of urban governance, not just for Seoul, but for cities around the world."

Korea's High Line, the MVRDV-designed Skygarden, opens in Seoul

2017-05-23T14:38:00-04:00

Ever since the High Line appeared above the streets of Chelsea in New York, cities across the globe have been working on creating their own variations of the civic project. In London, this iteration was to be the Thomas Heatherwick designed Garden Bridge. However, the project was marred by controversy due to suspicious funding and motives and was finally nixed by the Mayor back in April. Well, as the Guardian points out, London could've stood to take a few pointers from the South Korean capital of Seoul, whose MVRDV designed Skygarden opened over the weekend to much excitement.

The firm won the bidding process back in May 2015 and have since been working to transform an existing overpass in the heart of Seoul into a 983-meter long public garden, overlaying a matrix of Korean flora onto the 16m elevated steel and concrete structure. The Rotterdam-based architecture and urban design practice has gathered 50 families of plants, collecting around 228 species and sub-species and arrange...

Seoul's Lotte World Tower now the 5th tallest tower in the world

2017-04-05T12:23:00-04:00

Located in Seoul, the Lotte World Tower, designed by Kohn Pedersen Fox, has become the world’s fifth tallest tower, in the process knocking 1WTC—the tallest U.S. American building—out of the top five. At 555 meters tall, the Lotte World Tower has also surpassed Kuala Lumpur’s Petronas Twin Towers, which not long ago was among the tallest towers in the world. The Tower is nearly double the height of the now second-largest tower in Seoul, Three International Financial Center.

The Lotte World Tower houses retail spaces, offices, a luxury hotel, and an officitel—or studio-apartment style accommodations meant for the people who work in the building and which feature a slew of amenities. At the base of the building, the ten-story Lotte World Mall has already been open since 2014, and is a popular destination in the city, drawing 28.2 million people in its first year. That’s the equivalent of one out of every two South Koreans. The two building components are connected via interior pathways...

Korea's tallest tower poised to rival Dubai’s Burj Khalifa as iconic tourist attraction

2015-11-09T13:49:00-05:00

LDF aims to grow the Lotte Duty Free Shop World Tower into the world’s No.1 duty-free shopping destination. [...] Lotte is poised to turn the Lotte World Tower into a tourist attraction that can compare well with Dubai’s Burj Khalifa and Singapore’s Marina Bay Sands On top of that, the company plans to make the Lotte World Tower the largest tourism hub in Gangnam by equipping it with the world's highest observatory (located on the 123rd floor (555 meters high) [...].

Related in the Archinect News:

Seoul's Lotte World Tower complex passes safety inspections, allowed to reopen

2015-05-14T15:21:00-04:00

Lotte World Mall has finally received approval by the Seoul city government to open up its aquarium and movie theater, five months after the facilities were shut down due to safety concerns. [...] Lotte World Mall has been embroiled in several safety issues since it opened its doors in October. Several construction workers fell to their deaths during the construction of the annexed skyscraper [...].

Previously:

Construction in Seoul’s supertall Lotte World Tower surpasses 100th story – amid safety concerns

2015-03-31T18:30:00-04:00

With the completion of the 100th floor, Lotte Group invited a group of reporters on Thursday to take a peek at the Lotte World Tower, still under-construction, in Jamsil, southern Seoul. The building is currently the tallest building in Korea. [...] While the view is awe-inspiring, the fate of the Lotte World Tower hangs in balance, especially after the 2014 Sewol disaster which resulted in more than 300 people dead.

Previously: Mysterious Sinkholes Appear Near Construction Site of Supertall Skyscraper in Seoul