Pause where you can see the natural arch of Reynard’s Cave. To find out how it formed we need to travel back to the end of the last Ice Age, around 10,000 years ago, when glacial meltwater swelled the Dove into a powerful torrent. Icy waters cut down through fissures and faults in the rock like a knife through butter. The vertical crags and pinnacles we can see from here are harder bands of limestone that the water could not cut through, but just how did these natural caves and arches form?
Limestone has many joints and cracks. When acidic rainwater trickles into these joints, it dissolves and widens them into underground drainage systems, including tunnels, caves and caverns. As the river cut down through the limestone it intercepted some of these secret tunnels and caves, opening them up for the first time. Reynard’s Cave is the remnant of just such an old cavern, exposed as the Dove cut down through the limestone.