Tor (rock formation)

Hawk's Tor, on Bodmin Moor

This article is about a kind of hill. For Tor (disambiguation), see Tor (rock formation) (disambiguation).

A tor is a large hill, usually topped with rocks. The term is most commonly used in the South West of England - particularly with reference to the high points of Dartmoor, in Devon, and Bodmin Moor, in Cornwall. The term is notable for being, along with crag, one among a mere handful of Celtic loan-words (Old Welsh twrr, Scots Gaelic tòrr), primarily of a geographic or topographical nature, to be borrowed into vernacular English prior to the modern era.

Dartmoor represents one of the largest areas of exposed granite in the United Kingdom, covering an area of 241 square miles (625 square kilometres) (source: Dartmoor National Park). It is part of a chain of granite stretching through Cornwall, as far as the Isles of Scilly.

Theory holds that tors are the result of millions of years of weathering. In prehistoric times, when the land was covered in forest, rain water seeped into the ground and gradually weathered the bedrock through its natural cracks, or joints. Once the land became exposed, the weathering was accelerated, particularly during the Ice Age when freezing water expanded in the cracks. The result can be seen today in dramatic rock formations.

Some of the more durable granite survived to form the rocky crowns of Dartmoor tors. One of the best known is at Hay Tor, on the eastern part of the moor, whose granite is of unusually fine quality and was quarried during the 19th and early 20th centuries. Its stone was used to construct the pillars outside the British Museum in London, and to build London Bridge (now in Arizona). The last granite to be quarried there was used to build Exeter War Memorial in 1919.

Weathering has also given rise to circular ‘rock basins’, formed by the accumulation of water and the repeated freezing and thawing - a fine example is to be found at Kes Tor.

As the weathering of the tors continues, the rock is broken down into ever smaller sizes. Many hillsides are covered with loose rocks, known as clitter, which have provided ready building materials for thousands of years. Eventually the granite is weathered down to a level equivalent to sandy gravel - known as growan, which consists of individual crystals.

Ten Tors is an annual weekend hike on Dartmoor.

Highest tors on Dartmoor

• High Willhays (621m) N.B. This is not a Tor, Just the highest point
• Yes Tor (619m)
• Hangingstone Hill (603m)
• Great Links Tor (586m)
• Kitty Tor (578m)
• Fur Tor (572m)
• Great Kneeset (567m)
• Higher Dunnagoat Tor (560m)
• Hunt Tor (560m)
• Cosdon Beacon (550m)
• Lower Dunnagoat Tor (550m)
• Dinger Tor (550m)
• Devils Tor (549m)
• Rough Tor (547m)
• West Mill Tor (541m)
• Flat Tor (540m)
• Chat Tor (540m)
• Green Tor (540m)
• Steng-a-Tor (540m)

Other well-known Dartmoor tors

• Fox Tor (190m)
• Hay Tor (457m)
• Hound Tor (414m)
• Kes Tor (437m)
• Sheeps Tor (369m)

Other tors

• Glastonbury Tor
• Mam Tor