San Francisco Maritime National Historic Park
The San Francisco Maritime National Historic Park was designated as an NHP in 1988 and is located right next to Fisherman’s Wharf. The Maritime NHP consists of three main attractions: the Maritime Museum, Hyde Street Pier and the visitor’s center, which are kind of separated from each other, so expect some walking.
The museum is in a nifty building right in front of Ghirardelli Square. It’s a bit on the smallish side, but it’s free, so that’s no big deal.