Since many years the Seoul city planning Department has activated a process of enhancement of public pedestrian spaces and paths through the creation of a large infrastructural network able to fluidifying pedestrian paths and connecting different areas of the city at the different levels; ground, underground, superground. This process includes the project of re-structuring the Sewoonsangga citywalk. The project, which comes from the winning proposal of an international design competition held in 2017, provides the recovery and reconnection of urban spaces along the iconic megastructure and linear building complex of Sewoonsangga, in the heart of Seoul, which, since its construction in the late 60s, was equipped with elevated public citywalks. These superground public spaces, together with the existing ones at the ground level, are redeveloped and reconnected with other adjacent pedestrian infrastructures, alternating green, rest and commercial spaces, for over a 1,2 km lenght. The new urban infrastructure is called "open city platform" and it will be able to activate a spontaneous process of transformation of the existing Sewoonsangga complex, avoiding a "gentifrication" process. The Sewoon district, well known for its social and productive characteristics and for the presence of thousands of craft businesses, is trying to transform itself through shared and people participatory choices with a process that actively involves both the public administration and the citizens. The quality of the new Sewoonsangga citywalk system is based on its capacity to be transformed and in the same time to activate a continuous changes of its surroundings. Part of the existing citywalk was interrupted, functions were not able to bring quality to the public areas and there was a deeep disconnection of the Sewoonsangga complex different levels. The new citywalk reconnects and becomes a flexible infrastructure, able to change its behaviour based on the different time needs. The "continuous open platform" will dialogue with the city at two different scales. A first scale is the urban scale, the "Macro scale" which defines the platform as a continuous path able to reconnect many districts of the city from Jongmyo to Namsan and furthermore, a long pedestrian spine. The other scale is the "Micro scale". The open platform, activates and supports the transformation of the different districts which meets along its path. The platform adapts itself to the peculiarity of the different areas it meets, physically, conceptually and socially. The open platform through a Macro and Micro scale approach supports and activate a continuous transformation of the area in terms of community regeneration, Industrial restoration and mobility and pedestrian improvement. The open platform will be able to dialogue with the city in many ways activating the trasformation of the area through a process of pedestrian and mobility improvement, through a community regeneration and through an industrial restoration. Quality of life means for example less urban noise, easy spaces perception, safeness in walking, outdoor meeting spaces. That is why the projects gives a priority to the increasement of pedestrian and bike spaces as is the only solution to increase quality of life. We propose a continuous pedestrian path able to cross a big part of the city and able to connect many district of Seouls. An open pedestrian and flexible platform which can have possible future expansion based on the future urban transformations. Actually, except for the ground floor of INHYUNSANGGA – JINYANGSANGGA complex which has a commercial front, all the other levels of the complex are disconnected from the deck level, used mainly as loading and unloading area, with no commercial fronts. The aim of the new infrastructure is to overturn this situation, activating the creation of attractive trasparent fronts visually and phisically well connected with the pedestrian paths in all the four commercial levels of the complex and generating new social energy in the district.