Parson's Barn

Parson's Barn is a large sea-level cavern below the Ballard Point cliffs, between Studland and Swanage bays in the English Channel. Ballard Point is the headland of the Ballard Downs, an area of chalk downland, on the Isle of Purbeck in Dorset, southern England. Parson's Barn lies directly east of Studland, about 5 kilometres (3.1 mi) northeast of Swanage, and a few hundred metres south of Handfast Point and the Old Harry Rocks. Parson's Barn is the largest of several arches and caverns in this location and is 12 metres high at its mouth. The cavern was once used as a smugglers' cave. A large section has collapsed since then and has been eroded away by the sea. Now only a few chalk stacks, called the Pinnacles, remain.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).