If you're in the bay area, the Bay Model in Sausalito is a surprisingly interesting visit. It's a giant scale model of the entire bay area (accurate in two dime

If you're in the bay area, the Bay Model in Sausalito is a surprisingly interesting visit. It's a giant scale model of the entire bay area (accurate in two dimensions, compressed in height) with water pumped in and out repeatedly to simulate the tidal cycle and river flow. It was originally used to demonstrate that the Reber plan was flawed (computational modelling at the time was just not feasible), but if you look closely near SFO you can also see attachment lugs that look like they were used to examine the impact of runway extensions into the bay. It's probably not worth the trip into Sausalito on its own, but there's a bunch of background material on display that contextualises it well, and you can easily kill a couple of hours there.