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Upper Plym Valley

The Upper Plym Valley has a wealth of archaeological sites of all periods and types, many of which are impressive in themselves.  The importance of the area is reflected in the fact that it was taken into the care of the State in the 1970s; only the finest examples of sites and landscapes have been designated Properties in Care.

One of the most impressive and important sites on Dartmoor is the prehistoric ritual complex at Drizzlecombe, constructed around 4,000 years ago. Here can be found three stone rows and associated stony burial mounds (cairns), one of which, Giants Basin, is 22 metres in diameter and four metres in height   Other stone rows occur on Ringmoor Down and below Great Trowlesworthy Tor.  Further cairns can be found scattered throughout the area.

There are many examples of prehistoric settlement sites, probably constructed about 3,500 years ago; some lie close to the banks of the River Plym; others on the SW slopes of Higher Harter and Trowlesworthy Tors.  One of the largest, Whitten Knowles, has the remains of over 40 stone built round houses, or stone built round houses (hut circles).  Many of the settlements consist of dry stone-walled enclosures, with hut circles either within or adjoining the walls.  Some of the more complex sites, which have a number of enclosures adjoining one another, probably developed over a period of time.

There are no extensive prehistoric field systems here, but there are two long straight boundaries (reaves) located within the PAL; the Eylesbarrow reave on the MW edge and the Willings Walls Warren reave, to the SE, were originally constructed as territorial boundaries. Reaves appear on the ground as low stony, vegetation-covered banks. Farmsteads and fields created in the medieval period (probably about 700 years ago) and now abandoned can be found on Ringmoor Down and Hentor Warren in particular, but there are signs of medieval activity throughout the area.  The building remains, comprising low, vegetation-covered dry stone walls are generally of the longhouse form; the various field boundaries are stony banks, some of corn ditch form. Traces of cultivation, in the form of low ridge and furrow also occur in places.  Within the Whittenknowles prehistoric enclosure are the remains of a medieval settlement containing the largest longhouse on Dartmoor.

Five large rabbit warrens, probably 17 century creations, are spread along the valley and their distinctive pillow mounds, cigar-shaped and vegetation-covered, survive in large numbers. There are also a number of vermin traps. This is the largest concentration of warrening activity on Dartmoor and Ditsworthy is the largest warren in England.

Tin extraction was very important in the area and the heaps of spoil left by tin streamers survive along the entire course of the Upper Plym and its tributaries. It is likely that work first began in the early medieval period, about 700 years ago.  There are also numerous pits, dug to extract tin from the underground lodes.  Leats, associated with both industrial and domestic use are also present. Eylesbarrow Mine, which operated between 1814 and 1852 has been described as ‘arguably Dartmoor’s most important mine’.  Spread over a large area are a variety of structures and features including stamping mills, a smelting house, wheelpits, leats, tramways, shafts and adits.

There are several large areas which have been designated as Scheduled Ancient Monuments (SAMs), covering some 150 hectares and numerous individually scheduled monuments.

Part of this area falls within the South Dartmoor SSSI and Dartmoor SAC. Acid grassland, valley mire and Heather moorland dominate the area. UK BAP species are present within the valley mires and include: Insects- Scarce Blue-tailed damselfly, Small Red Damselfly. Birds- Snipe.

What it should look like: This site requires a mosaic of vegetation including short acid grassland (5 to 15 cm), Heather and Western Heath.  The heathland will ideally be managed on a rotation to provide a range of heights from 30 cm to recently burnt ground.  Areas of Western Heath with its component of Western Gorse may be permitted to grow away from archaeological interest and managed under an appropriate controlled burning regime for the habitat.  Some areas of Western Heath will need to be managed on a short rotation hence moving the vegetation towards a grassland community. There should be intervention to stop the spread of trees and scrub. Bracken requires control in some areas especially close to the mire at Sheepstor.

Page last updated: 23 Feb 2006
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