Caves can be found in the following areas of the island:
A cave has recently been reported to have been discovered on the Castletown Bay coast of Langness peninsula. Named Langness Seacave, it is 35m long and is partly tidal. The discovery was made in April 1994 by Max Moseley who documents his discovery in Cave and Karst Science, volume 24, number 1 (April 1997).
The cave is in Carboniferous age Langness Conglomerate. This member underlies the Castletown Limestone which is exposed in cliff sections nearby and which forms much of the southern portion of Langness peninsula. Where exposed in coastal section, the conglomerate is usually highly dissected by erosion along joints and veins, resulting in collapsed ground, sea caves, natural arches, narrow embayments and similar geomorphological features.
Map from MapQuest
For more information about the Isle of Man have a look at the Isle of Man Guide.