Beijing-based architecture studio OPEN Architecture has completed a double-shell concrete tower in Yantai, China. Named Sun Tower, 50-metre-tall structure features outdoor theater, digital exhibition spaces, library, caféand bar. Atop the summit is a unique semi-outdoor "Phenomena Space". Encompassing a total of 4,960-square-metre area, the movement of the sun as seen from the site's vantage point shapes the geometry of Sun Tower.