A geologist has claimed that the biggest cave in Britain is in Shetland, not England.
Jonathan Swale used a laser range-finder to collect his data at the Calders Geo sea cave at Esha Ness in the north west of Shetland Island.
He found it to be 60ft tall and spanning a floor area of more than 60,000 sq feet.
This makes it bigger than the cave at the famous Cheddar Gorge in Somerset, previously thought to be the biggest in Britain, which Mr Swale said has a floor area of about 32,000 sq feet.
Mr Swale went into the cave this week in his kayak with the range-finder, which his friend uses for shooting practice, and took measurements from multiple points on the cave walls.
The geologist, who is based in Shetland, went to the cave about a month ago to record basic dimensions and returned to get a more accurate picture.
He said: “The reading is still not perfect but it’s good enough to see that it clearly beats the other cave by some margin.
“I knew it was big. Shetland became a European geopark recently and we have the eighth longest sea cave in the world, Holl o Boadie on Papa Stour at 330yds, so I was wondering about some of the other sea caves in the area.
“The reason we have so many of them here is largely to do with the power of our seas, as well as the geology.”
The next steps are for more accurate equipment to be brought to Shetland.
Mr Swale said that a Wizard 3D laser scanner would be ideal but it is known to be very expensive.
Geos are linear clefts in a sea cliff that result from marine erosion along a line of weakness. Water drives air into the cracks in the rock and the pressure forces the rock to break off.
This repeated process is what enlarges the caves through time.