Bronze Age settlement

There are especially well-preserved concentrations of Bronze Age settlements and enclosures on Trowlesworthy, Willings Walls and Hentor warrens. The enclosures consist of low, fragmentary walls made of large boulders, while the settlements consist of roundhouses, with small terraces in the hillsides enclosed by low rubble or slab walls.

Some of the most distinctive Bronze Age remains on Dartmoor are the low, stony, earth-covered banks known as reaves. Made up of granite boulders and layers of turf, these were boundaries that demarcated zones of territory or shared pasture, and can be seen running for miles across the moorland. Over 125 miles of reaves have been identified on the moor. A good example in the Upper Plym Valley is Trowlesworthy Reave, which crosses the moor on the hillside below Shell Top. Elsewhere on the moor and on its fringes, many field boundaries in use today still follow the line of ancient reaves.

Medieval Farming

There is a notable absence in the Upper Plym Valley, as elsewhere on Dartmoor, of remains from the Iron Age and Roman periods. Environmental evidence has shown that the farmers of the Neolithic and Bronze Age cleared the woodland on Dartmoor, degrading the soil and creating moorland. By the end of the Bronze Age, it was not economic for farmers to live on Dartmoor’s fringes and the land became only seasonal pasture.

There is much evidence of occupation and activity in the medieval period, however. The lower, western, end of the Upper Plym Valley was gradually resettled from the 13th century, and at least six farms or smallholdings were established in the area up to the 18th century. Of these only the earliest, Trowlesworthy, established in 1272, remains in use.

The farmhouses are all of a typical Dartmoor longhouse design – rectangular buildings with a single entrance in the southern side. Around them are often smaller ancillary buildings and beyond these are the remains of their fields.

At Hentor, the fields contain the most complete examples of medieval ridge and furrow (strip cultivation) on Dartmoor.

Tin streaming

All along the floodplain of the Plym are ridges of stone and massive delvings into the river deposits. These are evidence of the tin-streaming industry that once flourished here and in the valleys all over Dartmoor, certainly from the 12th century and possibly even in prehistory.

The granite of the moor, as elsewhere in the South West, contains cassiterite (tin ore) which could be washed out of the gravel of the stream beds.

As the valley was worked, large amounts of waste gravel accumulated and were piled into stone banks. The tin ore was taken away to be crushed at stamping mills – one of which lies just above the confluence of the Plym and Shavercombe Brook – and smelted at workshops known as blowing houses. The remains of one blowing house are visible higher up the valley where the Langcombe Brook joins the Plym.