This triangular masterpiece was one of the first skyscrapers. Its knife-blade wedge shape is the only way the building could fill the triangular property created by the intersection of Fifth Avenue and Broadway, and that happy coincidence created one of the city's most distinctive buildings. Built in 1902 and fronted with limestone and terra cotta (not iron), the Flatiron measures only 6 feet (2m) across at its narrow end. So called for its resemblance to the laundry appliance, it was originally named the Fuller Building, then later "Burnham's Folly" (since folks were certain that architect Daniel Burnham's 21-story structure would fall down). It didn't. There's no observation deck, and the building mainly houses publishing offices, but there are a few shops on the ground floor. The building's existence has served to name the neighborhood around it -- the Flatiron District, home to a bevy of smart restaurants and shops.