Columbus Tower, also known as the Sentinel Building is a mixed-used building in San Francisco, California completed in 1907. The distinctive copper-green Flatiron style structure is bounded by Columbus Avenue, Kearny Street and Jackson Street, straddling the North Beach-, Chinatown-, and Financial-districts of the city. It is designated landmark number 33. The Transamerica Pyramid is the tallest skyscraper in the San Francisco skyline and one of its most iconic. Although the building no longer houses the headquarters of the Transamerica Corporation, it is still strongly associated with the company and is depicted in the company's logo. Designed by architect William Pereira and built by Hathaway Dinwiddie Construction Company, at 260 m (850 ft).