Sutro Tower is a Bay Area Icon. It is a steel tower that is used by 10 TV channels, 3 FM radio stations, satellite and cable providers and nearly two dozen public and commercial wireless communications services.
The 977-foot tower was completed in 1973 and is located between Twin Peaks and Mt. Sutro. Besides making TV transmission easier, it has become a huge feature of the San Francisco skyline:
And I got this one from across the Bay in Alameda: