Summary
The standing, earthwork and buried remains of a prehistoric relict landscape including an entrance grave, hut circle settlement, its associated field systems, and cairns. The site also includes the remains of later tinworks, and medieval and post-medieval fields systems.
Reasons for Designation
The prehistoric entrance grave, settlement, field systems and cairns, medieval and post-medieval field systems, and the post-medieval mining remains to the north-east of Lanyon Farm, Bosiliack are scheduled for the following principal reasons:
* Period/Rarity: the Bronze Age entrance grave and roundhouse settlement are representative of their respective periods and there is a presumption in favour of their designation when they survive to any substantive degree, as is the case here. The re-occupation of at least part of the settlement in the Iron Age provides evidence of a complex socio-political landscape that existed during this period;
* Survival: the site contains a diverse group of monument classes that survive well and together represent good evidence of the long-term management and exploitation of this area since prehistoric times;
* Potential: the site will contain further archaeological and environmental deposits that have not yet been excavated which will relate to the occupation of the prehistoric settlement and the character of upland agriculture. Later tin working activity contributes additional information concerning the character of the relationship between farming and mining;
* Documentation (archaeological): archaeological survey, combined with a series of excavations, has considerably enhanced our understanding of the form and survival of the monument;
* Group Value: the inter-relationship of the different elements within this landscape enhances the national importance of the monument as a whole.
History
To the north-east of Lanyon Farm, Bosiliack is an extensive relict landscape of prehistoric, medieval and post-medieval date. The site includes a prehistoric entrance grave, a hut circle settlement and its field system, as well as further field systems of medieval and post-medieval date and mining remains dating mostly from the post-medieval period.
EARLY BRONZE AGE ENTRANCE GRAVE
Entrance graves are funerary and ritual monuments dating to the later Neolithic, Early and Middle Bronze Age (c.2500-1000 BC). They were constructed with a roughly circular mound of rubble and earth, up to 25m in diameter, which contains a rectangular chamber. Excavations within entrance graves have revealed cremated human bone and funerary urns. The graves may occur as single monuments or in groups often associated with other cairn types in cemeteries. Entrance graves are one of several forms of chambered tombs found in western Britain and adjacent areas to the south, including the Channel Islands and Brittany. The entrance grave 533m north-east of Lanyon Farmhouse, Bosiliack was surveyed by the Ordnance Survey in 1960; there was a further survey in 1971 when it was described as a round barrow. An excavation by Charles Thomas in 1984, however, confirmed that it is an entrance grave which dates from the Early Bronze Age; radiocarbon dating of the cremated bone from the tomb indicated a date range of between 1690 to 1500 cal BC. It was restored following the excavation.
BRONZE AGE ROUNDHOUSE SETTLEMENT
Towards the latter part of the second millennium BC, the appearance of roundhouse (buildings of stone and wood) settlements reveal increasingly settled lifestyles with developed stock and arable farming. Roundhouses consist of low walls (stone or wood) or banks enclosing a circular floor area; remains of the turf or thatch roofs are not preserved. They may occur singly or in small or large groups and may lie in the open or be enclosed by a bank of earth and stone. Frequently traces of their associated field systems may be found immediately around them, sometimes indicated by area of clearance cairns and/or the remains of field walls and other enclosures. The roundhouse settlement some 350m north-west of the entrance grave at Bosiliack, is located on the west-facing side of a shallow valley. It was partially excavated in 1984 when Middle Bronze Age and Iron Age artefacts were recovered, and a further excavation was carried out in 2011. Analysis of the excavation archive and radiocarbon dating indicates that the settlement had a lengthy, if episodic history of occupation, with at least one hut circle being re-occupied in the Middle Iron Age.
POST MEDIEVAL MINING REMAINS
In the northern part of the site, to the north-east of the settlement is an area of post-medieval mining remains. Due to the lack of significant deposits of stream tin, miners in West Cornwall substantially turned to the exploitation of lode outcrops by at least the mid-1500s (Sharpe, West Penwith Survey, see Sources). According to the applicant there is a reference of 1584 to a tinwork known as Basilsacke. Some outcrops were worked using openworks or closely-set small shafts and pits (lode-back workings). With some notable exceptions, such as the deep mines in St Just District, mining activity in West Penwith remained relatively small-scale during the C17 and C18 and a fairly minor component of the local economy (Sharpe), although the area at Ding Dong Mine, adjacent to Bosiliack, was extensively worked.
Details
An extensive area of prehistoric remains situated in an upland area of open moorland to the north-west of Bosiliack. It includes an Early Bronze Age entrance grave; a Bronze Age hut circle settlement, its associated field systems and clearance cairns. The site also includes medieval and post-medieval field systems, and an area of post-medieval tin mining.
EARLY BRONZE AGE ENTRANCE GRAVE
The entrance grave is situated on a slight ridge in the eastern part of the site, just beyond the eastern extent of a prehistoric field system. It survives as a circular stony mound measuring approximately 5m in diameter and up to 1.1m high. It is defined by an outer kerb of seventeen or eighteen large granite slabs with an entrance on its south-east side which leads to a rectangular internal chamber of edge-set granite slabs. An excavation in 1984 uncovered evidence that the chamber had been opened previously, but that most of the primary floor deposits were undisturbed; these contained cremated human bone, charcoal, pebbles and sherds from plain ceramic vessels. The entrance was found to have been blocked by an upright granite slab. The entrance grave is located adjacent to an east-west alignment of boulders that mark the upper edges of a terrace or lynchet, although the relationship between these two features cannot be determined.
BRONZE AGE SETTLEMENT
The Bronze Age roundhouse settlement is situated on the edge of open moorland on the east side of a shallow upland valley in the western part of the site. The roundhouses are grouped into a roughly oval arrangement around an open space. A survey in the 1980s identified thirteen or more stone-walled houses comprising eleven single structures, two with two-rooms, and a three-roomed house. They all survive as low, stony walls with an external diameter of between 5m and-10m and an entrance sited mostly in the south quadrant. Excavations in 1984 and 2011 recovered quantities of charcoal, flint scrapers and Bronze Age pottery, including decorated sherds, from within some of the houses; one retained evidence of original floor level, while another contained a large pit, possibly a pit hearth. Evidence was also recovered for the multi-phase occupation of several houses indicating that at least part of the settlement was inhabited during the Iron Age. Located adjacent to one of the roundhouses (SW 42813443) is a socketed stone about 0.9m square and 0.5m above ground, with a circular depression 0.15m in diameter and depth, cut into the top. It is considered to be later in date than the settlement and is possibly a socket for a horse whim. Beyond the main concentration of roundhouses are at least four further houses which are dispersed singly in the surrounding fields. To the north and east of the settlement is an extensive field system that covers an area of approximately 45ha, some of which are likely to be of prehistoric date and contemporary with the settlement. They are defined by stony banks, some with upright stones that are rarely higher than 0.6m. A large number of small clearance heaps or cairns are associated with the fields. An archaeological survey of the area in 1984 identified further field systems that post-date the prehistoric settlement; these later enclosures are of varying size and plan and are bounded by banks of either turf or stone.
MEDIEVAL AND POST-MEDIEVAL REMAINS
On the upper slopes in the north-eastern part of the site are the remains of post-medieval tin mining, including lode-back workings and prospecting pits which are orientated north-west to south-east and extend over an area some 460m long. They survive as an area of closely-set small shafts, pits and spoil dumps. In addition there are larger mine shafts with platforms for horse engines and spoil heaps that overlie the earlier remains in places. Towards the south-eastern extent of the mining remains is a hollow way which, for much of its length, has banks up to 0.5m high to either side. It is aligned north-east to south-west, following a sinuous course, and it pre-dates the main mining remains.
