1. A cairn, 17.5m in diameter and 0.6m high, which has a recent shelter built into its NE side, is one of two similar monuments upon this summit (see Nprn304836).
To the NE is a possible small cairn, 1.7m in diameter and 0.2m high.
(source Os495card; SN88NW6)
RCAHMW AP955039/66-7
J.Wiles 15.04.02

2. The northernmost of two large, Bronze Age stone cairns on a local summit named Carn Biga, the other cairn being NPRN 304836. This northern cairn is 17.5m in diameter and 2m high, with a more recent cairn, 2.5m in diameter and 1m high, NPRN 289785 built on its centre. A shelter, NPRN 289623 has been built into the east side of the cairn, above which a drystone wall 1m high, NPRN 289786, had been constructed between the cairn centre and the shelter. A small cairn, NPRN 289622, was recorded just northeast of the cairn. When the site was visited in August 2006, it was observed that there was very little quartz in the earlier cairn, which was noticeable given the quantity of surface quartz in the area.
Peat wastage to the west of the cairn (recently noted by the Cadw Field Monument Warden) has exposed stone uprights which may form part of a circular arrangement.

David Leighton, & J.J. Hall, Trysor, 10 November 2014