Stroma is an island that was previously inhabited but whose population sank from a peak of 375 in 1901 to just 12 by 1961 and was abandoned. The final permanent inhabitants left when the lighthouse was automated in 1997.
There is a partly collapsed sea cave a short distance inland in the west coast that is known as The Gloup. It is connected to the sea by a naturally formed subterranean passage 151m long which follows a junction between two faults.
The Gloup was reputedly used by locals to store illicit alcohol and other contraband away from excise officers within a cave inside The Gloup only accessible at low tide, known as The Malt Barn.
It is reportedly possible to kayak along the subterranean passage but with extreme caution because any sea swell is amplified by the narrow passage confines.
References:
- Island of Stroma
- Scottish Sea Kayaking: Fifty Great Sea Kayak Voyages By Doug Cooper, George Reid