Though not a typical architectural attraction, this tower is nevertheless a well-known landmark among locals. Built in the 1970s to provide television reception to the city's hilly neighborhoods, this three-pronged antenna tower reaches 977 feet into the air atop one of San Francisco's tallest hills and is visible from just about anywhere in the city when it's not shrouded in fog. While the tower itself is off-limits to the public, there are walking trails that get very close to the base of the tower and offer great views of the surrounding neighborhoods.