Market Square has served as the catalyst for the resurgence of San Francisco’s Mid-Market area—it is Twitter’s world headquarters, and provides open space and retail amenity for more than 4,500 new residential units in the neighborhood. Capitalizing on historic architecture and underutilized alleyways (formerly Stevenson and Collin Alleys), Market Commons has been reborn as a vibrant L-shaped open space flanked by two newly restored buildings, one of which is an Art Deco icon.