Valley Forge Caves
The caves are in the base of a large sink 180 feet across and 30 feet deep 0.3 miles north of the memorial arch in Valley Forge State Park.
Cave #1 is a pit 20 feet deep. It is quite unstable and has not been entered.
Cave #2 is 20 feet from #1 and is a two foot high passage extending southeast for 40 feet to a rock fill.
(Pennsylvania Geological Survey, 1974)