Columbus Tower (Sentinel Building)

Columbus Tower (often called the Sentinel Building) is a flatiron-shaped, copper-clad building completed in 1907 at the corner of Kearny and Columbus. The building was purchased by filmmaker Francis Ford Coppola in the early 1970s and is home to his company American Zoetrope. Its distinctive green façade and triangular form make it one of San Francisco's recognizable historic commercial buildings.