Columbus Tower (San Francisco)

Columbus Tower stands at a unique point in the city where three distinct neighborhoods collide. Its sharp, triangular footprint is a result of the city grid where Columbus Avenue cuts diagonally across the traditional blocks of Kearny and Jackson Streets. Because of this layout, the building takes on a classic flatiron shape that reaches eight stories into the air. Its exterior is clad in copper sheeting that has weathered over the decades into a distinct, pale green patina.