Twitter's new global headquarters occupies floors 7 through 9 of the 11-floor Market Square complex, an iconic 1937 Art Deco landmark that once housed the San Francisco wholesale furniture mart. Until recently, the building--like the rest of its mid-Market Street neighbors--has been a casualty of urban blight. Twitter's occupancy marks the beginning of a long-overdue renewal for the area, which is adjacent to some of the city's most historic venues: Davies Symphony Hall, the War Memorial Opera House, the Asian Art Museum, and City Hall. This decision has subsequently attracted other tech companies to consider locations nearby. Twitter's new headquarters is the first workspace designed specifically for the company, with the intent to reflect and nurture the Twitter culture, enable creativity, and appeal directly to Twitter's bright and passionate staff. The space is subtly branded through the use of the Twitter logo and signature blue, natural wood, and a frequent twig motif. The once cavernous open space, including the building's original concrete columns, has become a great expanse of white benching systems, punctuated with informal seating areas, large and small conference rooms, break areas with pantries, banquettes, and easily reconfigured lounge areas, all complimented by art from local artists. A yoga studio, fitness room, and two very popular game rooms are also part of the mix. This variety of options takes full advantage of expansive floor plates and natural light at the window walls. An enormous cafeteria and gathering space known as the Commons offers a varied menu and includes a stage for group meetings and entertainment. It opens onto the park-like roof garden that covers almost half an acre and offers impressive skyline views of the Bay Area. IA collaborated with Lundberg Design.