The Underground Booty Squad
This extensive system of caves is home to the Tunnel of Terror "haunted house" every halloween. More or less the sister cave to the Ford mines, it has a similar design with many parallel cross passages of large dimensions. At one time, it was mined by the Ford plant.
The caves have also been known as the UNIVAC caves, being right underneath the former UNIVAC plant, and the Watergate caves, for a reason I don't know.