Like many ancient cultures, early civilizations in what is now northwest China worshipped the sun. In fact, a team of archeologists recently excavated a sun altar in the Xinjiang region that dates back three millennia. But looking to the heavenly body for meaning and affirmation transcends geographies and cultures, and it is in the distant port city of Yantai where even earlier such traditions emerged. This is also where the Ming Dynasty, which ruled from the 14th to the 17th centuries, would erect fortified watchtowers. The Sun Tower, by OPEN Architecture, references both, capturing an adoration of nature in a building that soars 50 metres tall above the shores of the Yellow Sea.

Fittingly, OPEN Architecture based the Sun Tower’s orientation on solar movement: Its outer shell is parallel to the noon sunlight on the equinoxes; the outdoor theatre’s axis points towards sunrise on summer solstice; and the entrance tunnel aligns with sunset on the winter solstice. The circular roof, meanwhile, was designed to be perpendicular to midday sunlight on the summer solstice.

Resembling a silo sliced in half, and sitting on a seashell-shaped plaza, the building fuses the iconography of the lighthouse and the sundial, while “paying tribute to nature and the passing of time,” according to the architects. It incorporates many cultural programs, including an outdoor theatre, digital exhibition areas, a library, a café and a bar.

The building is constructed from two layers of white concrete, which are connected and braced by slabs and ramps. The inner shell, punctured by holes that resemble lunar craters, absorbs and amplifies the sounds of the sea; at its base, the semi-outdoor theatre features a stepped stage and seating area that together with the building’s footprint creates a full circle that merges with the plaza.

A series of elliptical rings, resembling planetary orbits, radiates from the tower’s centre. These house the building’s circulation route and indoor spaces.

Finally, the apex is crowned by a “phenomena space” – an undefined void in an upside-down shell from which visitors can gaze at the ocean. Above is an oculus, which funnels rainwater to a small pool, where it swirls for nine minutes every hour, from 5 am to 9 pm, “working as a special time device.”

Symbolically and materially, water flows throughout the tower: The building’s plaza features fountains that celebrate the 24 Solar Terms of the traditional lunar calendar; their sprays synchronize with the sea’s high and low tides.

An instant icon, the Sun Tower is a sight to behold in and of itself and also provides incredible vantage points to its surroundings and to nature. It’s also designed to minimize its impact on nature through passive strategies: Among other measures, it utilizes tunnel cooling for fresh air supply, thermal mass to reduce indoor temperature fluctuation, and chimney effect to exhaust hot air. This might be one for the ages.