雙螺旋觀景塔

The Chenhu Migratory Bird Observation Tower is a 19.8-metre observation tower in the Chenhu Wetland bird sanctuary near Wuhan, China. Designed by Xiang Architects, the structure consists almost entirely of staircases arranged as a double helix, forming a continuous route through the tower. Each staircase ends at a short balcony-like platform with a glazed section, creating 24 staggered viewing points along the ascent. The staircases also form the primary structural system, replacing a conventional central core. Twenty-four standardized prefabricated elements wrap around a central three-metre-wide void, with counter-rotated steel braces supporting the structure.

The tower is entirely clad in steel, giving the observation point a metallic exterior across its staircases, platforms, and structural elements. The sanctuary surrounding the tower becomes home to more than 100,000 migratory birds each winter, with the elevated platforms positioned to provide views across the marshland. The double-helix circulation separates ascending and descending routes while maintaining access to the staggered platforms.