A multi-tiered brick fort at the water's edge at the south end of the bridge, with spiral granite stairs up to the roof.
Why it's unique
The only Third System fort built on the Pacific Coast, completed in 1861. The bridge's engineer redesigned the span so the fort would not have to be demolished, which is why a brick garrison sits underneath it today.
The Third System forts are an American series, and this is the one western example, so the claim is to the country.
Before you go
Go up the spiral granite stairs to the top tier, which is the reason to come: you look straight up into the bridge's underside. Roof access stops at 4:30, half an hour before the fort closes.
It is closed Tuesdays and Wednesdays, and cell service is limited, so download the NPS app first. Ranger talks run at 11:30, 1:30 and 2:30. Candlelight tours are ticketed in winter and announced on social media.
