Cheddar Gorge, England.
At almost 400 feet deep and three miles long, this is England’s largest gorge, and with its weathered crags and pinnacles, one of our most spectacular natural sights.
"Contrary to popular belief, Cheddar Gorge is not a collapsed cavern, but a fine example of a gorge cut by a surface river, and since left high and dry as drainage went underground. The gorge was formed by meltwater floods during the many cold periglacial periods over the last 1.2 million years. During these arctic episodes, the development of permafrost blocked the caves with ice and frozen mud. Snowmelt floods during the brief summers were forced to flow on the surface, carving out the gorge in the process.
Each successive periglacial episode caused further erosion. During the warmer interglacial periods, drainage was underground, creating the caves and leaving the gorge dry.”