Two Locks Caves are in the Beekmantown Limestone that strikes N. 30º E. and dips 80º E. and are developed along the bedding planes.

Two Locks Caves

     Several small caves and solution holes are developed in the bluffs along the C & O Canal, south of Two Locks. The northernmost cave is a 4-foot square opening in the cliff face, 20 feet above the river. It consists of a single room 10 feet in diameter and 5 feet high and is used as a roost by numerous pigeons. One hundred feet south of here is a fissure which extends south for 30 feet. The entrance to the largest cave is 150 feet to the south, in a small hollow 30 feet above the river. It trends northeast as a crawlway for 40 feet before opening into a somewhat higher passage with two side passages. These extend for short distances on both sides of the entrance passage as low crawlways.

(from ES3 -Caves of Maryland)