U.S. Army Corps of Engineers Bay Model

The U.S. Army Corps of Engineers Bay Model is a working hydraulic scale model of the San Francisco Bay and Sacramento-San Joaquin River Delta System. While the Bay Model is still operational, it is no longer used for scientific research but is instead open to the public alongside educational exhibits about Bay hydrology.

Source: Wikipedia — U.S. Army Corps of Engineers Bay Model (CC BY-SA 4.0)