The nearly three kilometers long suspension bridge connecting San Francisco and Marin County is definitely the best-known icon of San Francisco. Its construction was finished in 1937 and it was the longest suspension bridge till 1964.
The bridge can be spotted in numerous films (e.g. Invasion of the Body Snatchers, The Day the Earth Stood Still or Superman) and TV series (e.g. Charmed, which features the top of the bridge very often).
On both sides of the bridge, there are popular lookout points - an ideal place to snap some pictures. You can cross the bridge on foot or by bike but beware of the weather conditions and check the weather forecast before you set off - it gets cold and windy there.