Fort Point sits right beneath the southern arch of the Golden Gate Bridge, at the tip of the Presidio. The Civil War-era brick fortress is dramatically dwarfed by the bridge above it. Even when the fort itself is closed, the site is worth visiting for the perspective on the bridge's massive engineering and the views across to the Marin Headlands.
Film buffs will recognize the spot -- it is where Jimmy Stewart pulled Kim Novak from the Bay in Hitchcock's Vertigo. On good wave days, you can watch local surfers riding the swells that roll around the point.