My favourite building in New York City. The Fuller building, better known as the Flatiron building is located at 175 Fifth Avenue in the borough of Manhattan, and is considered to be a groundbreaking skyscraper. Upon completion in 1902, it was one of the tallest buildings in the city and the only skyscraper north of 14th Street. The building sits on a triangular island-block formed by Fifth Avenue, Broadway and East 22nd Street, with 23rd Street grazing the triangle's northern (uptown) peak.