Summary
The remains of a chamber or passage and creep of an above-ground fogou of probable Iron Age date, built into a wide field boundary, located to the west of Lower Boscaswell.
Reasons for Designation
Lower Boscaswell Fogou, comprising the remains of a chamber or entrance passage and creep, near St Just, Cornwall is scheduled for the following principal reasons:
* Period: as an important source of information about the pattern of settlement during the Iron Age period in south-west England;
* Rarity: fogous are an extremely rare and distinctive class of monument, being wholly restricted geographically to Cornwall;
* Survival: the remains of the fogou survive well, with the creep entrance being particularly intact;
* Potential: further evidence of the function of the fogou, and its relationship to a later courtyard-house settlement, will survive in unexcavated areas;
* Documentation: first documented in the mid-C19, the fogou was one of the first to be identified, and into the mid-C20 has consistently been included in the list of known fogous in Cornwall.
History
Fogous - a name derived from the Cornish for cave - are underground stone-built tunnels up to 30m long and 2m wide, usually with a long passage and sometimes with a chamber and side passages. Their drystone walls were initially built in a trench, roofed with flat slabs, and covered by earth although above ground examples survive. Fogous were mainly constructed in the early Iron Age (500 BC – 200 BC) and continued in use into the Roman period (AD 43 – AD 410). Fifteen fogous are known to have surviving remains, their national distribution being restricted to Cornwall, mainly in West Penwith and around the upper Helford River, although there is one at Indian Queens and one on St Mary’s on the Isles of Scilly. They are almost always associated with courtyard-house and other forms of contemporary settlements, including rounds (enclosed farmsteads) and hillforts. The original function of the fogou is not fully understood; safe refuge, storehouses for food or valuables, or as having a pre-Roman religious or ritual purpose have been proposed as possibilities. Fogous form a rare and distinctive class of monument and are important sources of information for the unique nature and pattern of settlement that developed during the Iron Age and Roman periods in south-west England.
The fogou on the western side of the village of Lower Boscaswell was first recorded in 1842 by the Reverend Buller, vicar of St Just, who described it as a subterranean cavern located in a small garden; he did not investigate the site further. In 1862 the Cornish archaeologist John Thomas Blight visited the site and was directed to a ‘vow’ or ‘giant’s cave’, where he found a mass of dry-stone walling on the seaward side of the village, adjoining a series of elliptical walled enclosures in use as gardens, but which were possibly a former courtyard-house settlement (not included in the scheduling). Blight measured an eight-feet (2.4m)-long passage roofed with large granite slabs, and in his account (see Sources) he considered that it must have extended into an adjacent elliptical walled enclosure to the east. He also noted a small blocked doorway (the creep) on the south-western side of the passage which he thought contained a side passage extending a considerable distance, as the ground around it was banked up for about thirty yards in a southerly direction. Between Buller and Blight’s visits, the passage remains were seemingly adapted for use as an animal shelter. Charles Henderson visited the site during the First World War and drew a plan of the ‘giant’s den’ and photographed the entrance, noting that the feature was in a ruined condition.
In 1954 a thorough excavation of the remains of the fogou’s chamber or entrance passage and creep was made by Clark, Ford and Thomas; it was only the second fogou to be excavated since William Copeland Borlase had worked at Carn Euny near Land’s End in the mid-1860s. Their description of the excavation (see Sources) revealed that the rab (earth) floor of the entrance passage or chamber sloped up to the east where it stopped abruptly at a modern dry-stone wall built to retain the circular enclosure beyond it. Due to its well-constructed doorway and a roof lintel placed flush with the face of the exit, they concluded that the creep terminated in the location where Blight had seen it. Their excavations continued the following year in the area within the elliptical garden, where a trench was dug east to west from its inner wall. This revealed a row of six courses of walling stones continuing east from the northern wall of the fogou passage. Its construction with larger stones in the upper layers changed to a pair of uprights with smaller stones in between after six feet (1.82m). Only tumbled remains were left of a southern wall, but both appeared to converge towards the centre of the garden where there was a clear step about two-feet below the modern surface level. The excavation concluded that the fogou had later been built-into what appeared to be a courtyard house with the eastern part representing an unroofed slope and the western part supporting capstones into the passage. Many sherds of pottery ranging in date from the Iron Age to the C19 were found within the filling of the covered passage and from the enclosure. The prehistoric pieces may have been deposited from elsewhere as dumped material although a single fragment of later Iron Age pottery was found on the rab floor in the garden beneath one of the fallen stones from the southern wall; this was taken as confirmation that the monument was used perhaps as early as the second century BC. Locally-produced pottery, quartz beach-pebbles, and finds dating up to the present day were also found. An opening made on the east side of the passage through to the garden during the excavation was roughly filled with a dry-stone wall when work was complete.
In 1960, the Ordnance Survey (OS) found the remains of the fogou entrance chamber or passage to be 3m long, averaging 0.6m high with two apertures: one on the west representing the remains of an entrance to a passage running west towards the great wall, and one on the south-west being the creep, 0.7m square. The OS also described, but did not classify, a dry-stone wall on the east side forming part of the enclosure, and a platform of stone and earth, extending south with a thick field wall on its east and being 1m high at the north end. The fogou was first shown on OS mapping in 1978.
To the west of the remains of the chamber or entrance passage was a ‘great wall’ 12-feet (3.6m) wide, running east to west, and gradually narrowing as it extended towards the sea for 96 feet (29m). The 1954 excavations concluded that the historic western entrance to the fogou would have been on the north side of the wall at its widest point, as the current entrance appeared to have been created by relatively-recent blasting to create an opening. This was not investigated further. The ‘great wall’ is shown on a 1957 geological map of the St Just mining area, but by the time of Weatherhill’s survey of courtyard houses in West Penwith in 1982 the ‘great wall’ had been removed. In 2019 a geophysical gradiometer survey was undertaken in the field to the west of the fogou. No substantial evidence of features which could relate to the fogou (such as a continuation of a passage) was found, and no trace of a ditch or any other evidence from the ‘great wall’ was discovered.
In 1992 the fogou was visited by Mcneil Cooke (see Sources) who summarised much of what was found earlier, but also proposed that the main passage originally terminated within the elliptical garden plot and was entered from the creep to the south-west, with the line of the passage perhaps continuing either west, or north-east.
Details
PRINCIPAL ELEMENTS
Located at the top of a gentle north-west facing slope approximately 91m above sea level and overlooking the Atlantic Ocean, is the remains of an Iron Age above-ground fogou comprising a stone-built entrance passage with a stone-slab roof, and a creep with a slab and lintel opening. The passage is built into a substantial field boundary on its eastern side which also forms part of the walling of a possible former courtyard house, later a garden plot, into which the passage extended.
DESCRIPTION
Lower Boscaswell fogou is likely to have been constructed in the Iron Age, perhaps pre-dating a possible courtyard-house settlement to its east, but likely to have once related to it. The fogou sits at the top of a slope overlooking fields and the coast to the west, and in front of its western entrance is a patch of tumbled rock, likely to be from field clearances.
The fogou is built into a thick dry-stone wall field boundary on its eastern side, approximately 2m high and 2m wide. This also forms the altered eastern wall of a former courtyard house, later an oval garden plot, into which excavation suggests that the passage once extended and possibly terminated. The entrance on the western side is approximately 2m wide and 0.5m high with a granite lintel which shows signs of blasting; this was probably done in the mid-C19 to provide an access to the chamber for livestock. At the base of the entrance is a substantial granite slab, approximately 1m long by 0.5m wide, and the sides of the opening are built up with granite blocks and dry-stone walling. Inside are the remains of an entrance passage, running roughly north-west to south-east, and approximately 1.2m high and 2m wide. The passage is lined with dry-stone walling (including a section on the eastern side which was rebuilt following excavations in 1954-5) and has two large granite roofing slabs. To the south-west is a creep passage approximately 1.2m long, 0.6m wide and 0.8m high. Its south-western entrance has flanking granite jambs and a lintel. The floor of the passage is compacted earth.
