Happy 80th birthday to the Golden Gate Bridge. On this day in 1973, this iconic bridge first opened. With towers extending 700 feet into the sky and over 100 feet beneath the San Francisco Bay, the bridge is an engineering marvel. In addition to driving, you can walk or bike the entire length of its 1.2-mile expanse, bounded on either side by spectacular scenery. Photo from Golden Gate National Recreation Area courtesy of Bruce Getty.