Sun Tower provides a much needed cultural hub for the growing population of Yantai's Yeda Development Zone. Established in 1984, the Zone transformed the area, which consisted mainly of fishing villages, into a district of industry and tourism.

OPEN Architecture conceived the project’s design as a celebration of the area’s historical connection to the sun and sea. It is one of the earliest regions in China where ancient sun-worshiping occurred and where Ming Dynasty-era watchtowers were erected. The structure’s design also features a contemporary take on the typology of lighthouses.

Sun Tower’s curving volume features large openings on one side, with its viewing platforms and ground floor theater facing the seafront. The approximately 164-foot-tall building was constructed from two layers of slanted concrete shells, connected and braced by horizontal slabs and ramps. These components were created in close collaboration with Arup.

The orientations of the tower’s various spaces were informed by meticulous studies of the sun. The northern edge of the building is parallel to the noon sunlight of the equinoxes, while the entrance tunnel aligns with the sunset during the winter solstice. 

A semi-outdoor theater is located at the center of the tower, which was oriented with its central axis pointing towards the sunrise over the nearby Zhifu Island on summer solstice.

The building’s concave inner shell absorbs the sounds of the ocean, which is amplified back through the structure to the amphitheater at the base. At this level, a series of elliptical rings, resembling planetary orbits, spread out from the tower. 

They are joined by a water channel, which is carved into the stone pavement. The intersections between the rings and the water channel mark the structure’s shadow at specific hours during the equinoxes. Additionally, one outer ring includes a series of fountains that celebrate the 24 solar terms of the traditional Chinese calendar.

At the top of the tower lies the library and the “Phenomena Space”. This Space is a semi-outdoor observation deck that features an overhead oculus opening, which allows rainwater to enter and be collected in a serene pool installation.

Throughout the building, exhibition spaces are featured around the winding pedestrian ramps with digital screens and projections. Hanging points in the concrete walls and ceilings were also added for displaying objects.

Sun Tower employs various passive strategies to reduce its overall energy consumption. It utilizes tunnel cooling for fresh air supply, thermal mass to reduce indoor temperature fluctuation, operable openings on both shells to improve cross-ventilation, and the chimney effect to remove hot air.