Reasons for Designation
Kerbed boulders, a type 1 monument highlighting a special natural feature, are one of a diverse range of ritual monuments dating to the later Neolithic and early Bronze Age (c.2500-1500 BC). They were constructed with a kerb of small upright slabs surrounding a natural ground fast boulder: the kerb slabs may either touch to form a continuous row or may be spaced apart. Kerbed boulders have been recognised comparatively recently as a class of prehistoric monuments which combine elements present in other types of contemporary ritual and funerary monuments. The emphasis placed on natural features, with an implied reverence for them, is clearly evident on a larger scale in south west England in prehistoric cairns and the choice of distinctive hills for Neolithic hilltop enclosures. The use of a ring of upright slabs as a visible means of indicating reverence or a sacred area occurs widely in prehistoric contexts, notably in the form of stone circles and the prominent kerbs and stone settings around many funerary cairns. Under a dozen kerbed boulders are currently known nationally, from Dartmoor, Bodmin Moor and the Isles of Scilly, but this number is expected to rise as modern perception of them increases. They form a very rare monument type providing valuable insights into the ordering of the landscape within prehistoric belief systems. Stone hut circles and hut circle settlements were the dwelling places of prehistoric farmers. Most date from the Bronze Age (c.2000-700 BC). The stone- based round-houses consist of low walls or banks enclosing a circular floor area the remains of the turf, thatch or heather roofs are not preserved. The huts may occur singly or in small or large groups and may lie in the open or be enclosed by a bank of earth or stone. Frequently traces of their associated field systems may be found immediately around them. These may be indicated by areas of clearance cairns and/or the remains of field walls and other enclosures. The longevity of use of hut circle settlements and their relationship with other monument types provides important information on the diversity of social organisation and farming practices amongst prehistoric communities. They are particularly representative of their period.
The characteristic field systems of strips often bounded by banks and ditches and filled with ridge and furrow attest to the farming practices of the medieval period.
The china clay industry originally developed in conjunction with the production of fine ceramics, chiefly porcelain, which had been known to the Chinese for centuries but were not produced elsewhere. In 1746 William Cookworthy discovered kaolin in Cornwall of a finer quality than anywhere in Europe. Combined with the locally available china stone which was mixed with the kaolin to form a paste it became possible to produce fine quality ceramics. The kaolin was of immense significance to other industries including paper, paint, pharmaceuticals and for agricultural purposes to name a few of many. In the early 20th century there were approximately seventy individual kaolin producers and in common with many industries investment was poor and over production was high. By 1910 the major markets were North America and Europe and much of the product was used by the paper industry. At this time the china clay producers in Devon and Cornwall had a near monopoly within the world market. Kaolin is extracted from the granite in which it is found using water. Originally washed off by channelled water at the surface the process became more mechanised with time until high pressure jets called monitors were employed. The clay was carried in suspension and was pumped from the clay extraction quarries or 'pits' via refining channels. The waste micas and sands in the resultant slurry were trapped en route. The material then entered settling tanks where it remained for up to three months of sedimentation. Once partially solidified the clay was transferred to the 'dry' or kilns where it was spread over heated pantiles to dry thoroughly before being cut into blocks. The china clay industry is still economically of significant importance to this region.
Cornwall and West Devon, has been one of the major areas of non-ferrous metal mining in England. It is defined here as prospecting, extraction, ore processing and primary smelting/refining, and its more important and prolific products include copper, tin and arsenic, along with a range of other materials which occur in the same ore bodies. Throughout much of the medieval period most of the tin was extracted from streamworks, whilst the other minerals were derived from relatively shallow openworks or shafts. During the post-medieval period, with the depletion of surface deposits, streamworking gradually gave way to shaft mining as the companion to openworking methods. Whilst mining technology itself altered little, there were major advances in ore processing and smelting technologies. The 18th century saw technological advances turning to the mining operations themselves. During this period, Cornish-mined copper dominated the market, although it was by then sent out of the region for smelting. The development of steam power for pumping, winding and ore processing in the earlier 19th century saw a rapid increase in scale and depth of mine shafts. As the shallower copper-bearing ores became exhausted, so the mid to late 19th century saw the flourish of tin mining operations, resulting in the characteristic West Cornish mining complex of engine houses and associated structures which is so clearly identifiable around the world. Technological innovation is especially characteristic of both mining and processing towards the end of the century. From the 1860s, the South West mining industries began to decline due to competition with cheaper sources of copper and tin ore from overseas, leading to a major economic collapse and widespread mine closures in the 1880s, although limited ore-extraction and spoil reprocessing continued into the 20th century. The multi period archaeological landscape 430m north of Tredinney survives well and provides archaeological and environmental evidence for rare ritual, developing agricultural and burgeoning early industrial features in a fascinating palimpsest which manages to encapsulate so much of the distinct and unique history and development of this characteristic region on Britain.
The monument includes a multi-period archaeological landscape, situated on the south east facing slopes of Tredinney Common. This rich landscape includes ritual, agrarian and industrial remains ranging in date from the prehistoric to post medieval periods. The ritual element includes a kerbed boulder which survives as a large saddle shaped boulder of approximately 5m long, 2.5m wide and 0.8m high with around ten large stones set around it which are from 1m to 1.4m long, 0.3m to 1m wide and 0.4m up to 0.7m high. On the north west side five of these stones form a 'box' which has been interpreted as a possible cist. It is known locally as 'Tredinney Common Barrow'. The agrarian landscape includes an area of both prehistoric and medieval fields and forms part of an originally more extensive system. The irregular, almost rectangular, fields are prehistoric in character and the layout suggests a sequential apportionment of arable use up the slopes of the hill. Two possible stone hut circles have also been identified within the prehistoric field system built against the lower level boundaries. The boundaries survive as substantial lynchets with boulder-built walls which have been modified in places to produce the characteristic strip systems of the medieval period. However, one area to the east contains only strips defined by low linear banks of up to 2m wide each with a single shallow ditch, and this area appears to be wholly medieval in date. Further agricultural evidence is provided by field clearance cairns, which may be of prehistoric origin and medieval or post medieval ridge and furrow. On the north west side a bank bounds the strip fields and also forms a parish boundary, further marked by boundary stones. Post medieval agricultural evidence is provided by a livestock pool and wild fowl pool with Tredinney Lidden and Hide. There is also evidence for peat cutting. Industrial activity survives in the form of a china clay works of early-19th century date. From a reservoir formed behind a 5m wide and 1.5m high dam four leats carried water past some earlier workings to the main pit which survives as an elongated quarry. This is flanked by the partially standing walls of a pumping house which raised the clay slurry into a series of channels across a mica dam to the settling pits, and to the east is a further building possibly the powder house for Tredinney Mine. To the south are the series of linear mica and sand dumps, accessed originally via a series of tramways. To the north and east are the pits and associated spoil heaps for tin prospecting and lode-back workings of Tredinney Mine. Further features include shafts, a horse engine platform, and low ruins of an engine house, a boiler pond and a possible count house.
PastScape Monument No:-421085, 420620