The biggest cave in Britain can be found in Shetland, a geologist has claimed.
Jonathan Swale used a laser range-finder at the Calders Geo sea cave at Eshaness.
He said he found it to be 60ft tall and spanning a floor area of 5,600 square metres.
Mr Swale said this made it one-and-a-half times as big as the biggest cave at the famous Cheddar Gorge in Somerset.
The geologist said the largest cave crown now seemed to belong to Shetland.
Mr Swale told BBC Scotland of his laser range-finder study: "This is possibly the biggest cave chamber in Britain and that's what tempted me to come back."