sculpted by sunlight: OPEN architecture completes 'sun tower'

a tower inspired by the path of the sun

OPEN Architecture’s newly completed Sun Tower is a distinctive cultural venue in the Yeda Development Zone in Yantai, China. Rising fifty meters (164 feet) over the coastline, the concrete structure combines an observatory, outdoor theater, exhibition spaces, a library, café, bar, and the unique Phenomena Space, all housed in a conical form inspired by the path of the sun. Located on the Yellow Sea’s coast, the Sun Tower brings a contemporary architectural landmark to a region with a rich history, establishing an iconic destination for the city’s residents and visitors.

Since its establishment in 1984, the Yeda Development Zone has evolved into a center for industry and tourism. The arrival of the Sun Tower meets the growing demand for cultural and community spaces, providing a venue that encourages engagement, environmental awareness, and social interaction for the area’s expanding population and visitors.

the design reflects the region’s history of sun worship and coastal watchtowers | image © Jonathan Leijonhufvud

celebrating the link between the sun and sea

With its Sun Tower, the design team at OPEN Architecture celebrates Yantai’s deep connection to the sun and the sea. Reflecting the region’s ancient history as a site of sun-worshipping and the Ming Dynasty’s watchtowers, the Sun Tower serves as a modern take on traditional lighthouses. This multifunctional structure is designed to embody the changing passage of time, anchoring the community in natural cycles and the historical reverence for solar movements.

The tower’s curved form, marked by large openings on the seaward side, provides platforms and viewing areas overlooking the coast. Constructed with two layers of slanted concrete shells, reinforced by horizontal slabs and ramps, the structure was engineered in collaboration with Arup to withstand coastal conditions and the unique design challenges. This robust form ensures structural durability along with a direct connection to the oceanfront.

the Sun Tower combines a theater, galleries, library, café, bar, and ‘phenomena space’ | image © Iwan Baan

open architecture learns from the solstice

Careful solar studies informed the design of the Sun Tower. Its northern edge aligns with the noon sunlight of the equinoxes, while the entrance tunnel frames the sunset on the Winter Solstice. The central semi-outdoor theater is oriented toward Zhifu Island, aligning with the sunrise on the Summer Solstice, thus allowing visitors to experience solar events from within the building.

Facing the Yellow Sea, the tower’s concave inner shell amplifies the sound of the ocean, resonating through the structure to the amphitheater at its base. A series of elliptical rings radiates from the central plaza, symbolizing planetary orbits. These rings intersect with a water channel carved into the stone pavement, marking building shadows during the equinoxes, while an outer ring celebrates the twenty-four solar terms from the traditional Chinese calendar with a series of fountains.

the 50-meter-tall tower features two slanted concrete shells facing the Yellow Sea | image © Jonathan Leijonhufvud

The top of the Sun Tower houses a library and the Phenomena Space, where visitors can enjoy panoramic ocean views. This semi-outdoor observation deck features an oculus that lets rainwater collect in a peaceful pool, adding a contemplative aspect to the architectural experience.

As visitors ascend the pedestrian ramps winding through the structure, they encounter exhibition spaces with digital screens and projection surfaces, supported by strategically placed hanging points for various displays. The Sun Tower employs passive design elements, such as tunnel cooling, thermal mass for temperature stabilization, cross-ventilation, and a chimney effect for air circulation, all aimed at minimizing energy consumption.

the tower meets local need for a community and cultural center in Yantai | image © Iwan Baan