At 2100 Bridgeway in Sausalito, the U.S. Army Corps of Engineers runs a visitor center around a working hydraulic model of San Francisco Bay and the Sacramento–San Joaquin River Delta. The Corps calls it “the only one of its kind in the world.”
Why it exists
Atlas Obscura says the Corps built the model in 1956–57 to show what would happen if the South Bay were dammed and filled in, as had been proposed. The simulated tides showed the results would be disastrous for the bay, and the plan was shelved. The model covers more than 1.5 acres. Water flows through the Delta, into the bay and out through a miniature Golden Gate, and visitors can walk around the whole thing.
More than the model
Atlas Obscura says the center also has exhibits on Bay Area watercraft, the Marin shipyard, World War II and the working bay today. The Corps says group tours are available and can be tailored to different technical levels.
Hours and cost
The Corps lists hours of 9 a.m. to 3 p.m. Tuesday through Friday and 9 a.m. to 4 p.m. on Saturday. The center is closed Sundays, Mondays and all federal holidays. When a federal holiday falls on a Monday, it's also closed the Saturday before. Admission is free, and donations are welcome.