Datong Art Museum is China's 32,000 square-meter "Museum of the 21st Century," one of four major new buildings within Datong New City's cultural plaza. The form by Foster + Partners is conceived of as an erupted landscape, with the entire museum sunk into the ground and only the roof peaks visible at ground level. The four interconnecting pyramids are clad in earth-toned Corten steel which will weather naturally over time. A clerestory between each volume creates an internal play of light and shade, while illuminating the building from within to create a beacon at night. The interior is designed to be highly flexible and accommodate changing programs. The Grand Gallery can be subdivided to create individual exhibition spaces, with services fully integrated into the structure. Arranged around sunken courtyards to capture daylight are the children's gallery, group entrances lobby, cafe, restaurant, and support spaces. High-level skylights use natural light while minimizing solar gain, and a high-performance enclosure further reduces energy use.