The Llancayo Farm Roman marching camp (NPRN 409178) generally follows the alignment of an early Bronze Age barrow cemetery (NPRN 409179 ? northern cluster; NPRN 420981 ? central concentric barrow; NPRN 414954 ? southern three barrows). which strikes across the river bend of the Usk appearing to `separate? the riverine lowlands of the meander from the rising ground of the wider valley. A localised hillock underlies the eastern side of the camp and may originally have made the barrows more prominent in the landscape. The northern and eastern ditches of the Roman camp were clearly set-out on two of the round barrows, which were probably deliberately levelled during camp construction.

As with the cropmarks of the camp, the barrow cemetery was steadily revealed during aerial photography from 2009-2012. A group of four circular ditches, representing the remains of ploughed-out prehistoric barrows were identified as cropmarks in 2009. The group comprised a larger enclosure or barrow, c. 35 metres in diameter at SO 2645 0332, and three smaller barrows to the west and north ranging in diameter between 11 and 14 metres. The largest enclosure and a second barrow are bisected by the east-west ditch at the northern end of the Roman marching camp.
Further aerial reconnaissance in 2011 revealed a second group of two roughly circular enclosures or barrows (NPRN 414954) to the south visible as cropmarks at SO 3668 0280. Both were c. 35 metres in diameter and situated immediately outside of the south-east corner of the marching camp, but were only recognised as barrows when mapped from aerial photographs and seen in the wider context of the site.

Aerial reconnaissance in March 2012 revealed a further concentric barrow (NPRN 420981) measuring 36m in diameter (at SO 3657 0315) mid-way between the two known groups and also bisected by the Roman camp ditch.

This is one of the larger lowland early Bronze Age barrow cemeteries known in Monmouthshire and appears to have a deliberate relationship with the topography of the river meander. Its presence is one of the earliest indicators linking heightened ritual significance to this particular locale.

Reference:

Davis, O. and Driver, T. 2015, Llancayo Farm Roman Marching Camp, Usk, Monmouthshire, Archaeologia Cambrensis 163 (2014), 173-184