The Sun Tower's interior features large ramps and exhibition spaces
Reaching a height of 50 m (164 ft) in Yantai, eastern China, the Sun Tower, by OPEN Architecture, cuts a remarkable figure on the shoreline. The curving observation tower functions similarly to a massive sundial and marks the changing of the seasons.
The Sun Tower's design is inspired by the area's ancient history of Sun worshipping, as well as the watchtowers that were long ago used to warn Chinese Emperors of possible seaborne attacks. Created in collaboration with engineering giant Arup, its curving form has been constructed from two layers of slanted concrete shells that help echo the sound of the waves.
"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," explains OPEN Architecture. "Sitting at the center of the Sun Tower is a semi-outdoor theater, which has been orientated with its central axis pointing towards the sunrise over Zhifu Island on Summer Solstice.
"Facing the ocean, the concave inner shell absorbs the sounds of the ocean, amplifying back through the structure, and down to the amphitheater at the base. Radiating from the center of the Plaza is a series of elliptical rings, resembling planetary orbits. A water channel is carved into the stone pavement. The intersections between the rings and the water channel mark the building shadow at specific hours during the equinoxes, and one outer ring features a series of fountains that celebrate the 24 solar terms of the traditional Chinese calendar."
At the top of the structure is a library and viewing point, plus a so-called "Phenomena Space" that hosts a semi-outdoor observation deck. This contains an oculus opening that allows rainwater to enter and be collected in a small pool installation.
Further down the tower, exhibition spaces containing digital screens and projections are formed around winding pedestrian ramps that rise through the structure. Additionally, a ground-floor theater faces the sea.
OPEN Architecture turned to passive strategies to help manage the Sun Tower's interior temperature, including encouraging cross-ventilation by installing operable openings on both shells, and removing hot air through the chimney effect.
OPEN Architecture has a real knack for producing unusual buildings and the Sun Tower follows the rock-like Chapel of Sound and otherworldly Space Crystal.