Bourn Hall Ringwork

Description

Bourn was the seat of the barony of Picot de Cambridge who has a castle at this place, of which the moat and other vestiges remain. The castle is said to have been burnt down in the Baron's Wars during the reign of Henry III by Robert de Lisle'. John Layer (1640) says 'Alan de Turre seemeth to be of the castle there, for aunciently there was a high castell ye ruines and monuments remaining their this day'. There is little doubt that Picot, the Domesday tenant, himself was the builder of the keep and bailey castle whose faint traces are now to be see round Bourn Hall, as he gave to the canons of Cambridge (afterwards Barnwell) 'the church of Brune with the chapel of the castle'. Whatever structure once stood here, all trace of it has disappeared, and even the earthwork has been so far obliterated that any exact description of the site is impossible. Its original form seems to have comprised a large banked and ditched inclosure of about 3 acres with a smaller horseshoe bailey down the gentle slope of the NE. There are signs of an original entrance to the bailey at the NE extremity. The British Museum Stowe MS (1025, 25) written before 1760 probably by Dr Charles Mason, Fellow of Trinity College, describes the castle as 'circular, about 160 yards in diameter'. It had a parapet walk 'between the ditch and inner vallum'. A plan on the same MS shows the inner ring nearly complete with a gap less than one sixth of the circumference in front of the house. The plan (in VCH) does not include the bailey but shows its point of junction with the keep. (VCH 1948)

Bourn Castle (N.G. TL 322561), the castle of Picot of Cambridge, sheriff of the county in 1086, now consists merely of two adjoining banked and ditched enclosures, much damaged by the construction of Bourn Hall and Hall Farm with their outbuildings and gardens. The remains lie on the level top and N.E. slope of a hill of boulder clay 196 ft. above O.D. That part of the monument lying in the grounds of Hall Farm was inaccessible to the Commission and this survey is therefore incomplete.
The S.W. enclosure is the main one and takes in most of the hill top; it is circular, 450 ft. in diameter, but has been almost obliterated on the N.E. The ditch, water-filled on the S.E., where it is widest, is 30 ft. to 45 ft. wide, 6 ft. to 10 ft. deep and 13 ft. to 32 ft. wide across the bottom. The internal bank survives on the W. and S.E. but has been altered on the W. in the 17th century to form a raised walk (see Monument (2) above); on the S.E. there is a stretch of rounded bank 80 ft. long, 30 ft. wide and 2 ft. high. The original entrance may have been on the N.E. The interior has been much altered; the Hall stands on a rectangular platform 2 ft. high. When a mid 18th-century antiquary, perhaps Dr. C. Mason, visited the site the rampart of the S.W. enclosure was better preserved and there was a berm between it and the ditch. (B.M. Stowe MS. 1025, 25).
The N.E. enclosure, crescentic in plan with the points placed against the S.W. enclosure, measures some 270 ft. N.E. to S.W. by 300 ft. N.W. to S.E. The ditch is traceable on the N. as a hollow 66 ft. wide, 3 ft. deep and 13 ft. across the bottom. There are indications of an internal bank and slight traces of a causeway across the ditch on the N.E. (RCHME)