The Tomeens of Tulla comprise a series of short river caves located in a limestone inlier in the drift-covered lowlands of eastern County Clare. There are ten caves spanning a 500 m long section of a tributary of the Hell River. The caves are separated from each other by surface collapses which leave 30% of the river course open to the sky. Two stream oxbows and a complex of dry oxbows and side passages add to the overall length of the system.