As featured on Time Team in January 2004, here's what the Channel 4 web site had to say about the site and the programme:
Further excavation on the shore indicates the site of a small ritual henge monument. Complete with entrance facing the loch, the henge contains a stone marker to align the entrance with a landscape feature in the distance where two hills meet. It was later calculated that this point on the skyline would mark the position of the rising sun on the spring and autumn equinoxes.
The RCAHMW record, predating the Time Team excavation, describes the site as a henge, hut circle, barrow or cairn (keeping their options open there):
It measures 12.0m overall and comprises a level, circular platform 7.4m in diameter, surrounded by a ditch 1.1m wide and 0.2m deep, outside which there is a bank 1.2m wide and 0.2m high, revetted externally by a discontinuous line of small horizontal blocks. The bank is broken on the SE, where there is a gap leading to a causeway across the ditch. Both gap and causeway, about 0.6m wide, are slightly mutilated.