Happy birthday Sutro Tower! One of our favorite San Francisco landmarks turned 40 years old this week.

The tower, San Francisco’s tallest structure at 977 feet and 1,811 feat above sea level, made its controversial debut in 1973 to improve TV signals in San Francisco. It started transmitting its first signals on July 4 that year.

Many locals, included celebrated Chronicle columnist Herb Caen, were not happy with the new installation and its imposing presence on the skyline. Caen gave it the nickname Sutro Monster and Space Claw.

The tower sits on Mount Sutro and is named after former San Francisco mayor Adolph Sutro, who lived in a mansion—and probably had the best TV reception in the Bay Area—about 100 feet away.

Sutro Tower is still used by 11 TV station, and several radio stations, public safety organizations and for wireless communications.

Check out the (shaky) view from the top:

Photo Credit: SutroTowerSF