Part of slate quarry complex (NPRN 402787). A small near square building, 6 m by 5.5 m in area. Only three walls survive, two of which are 0.55 m wide and survive up to 1 m in height. The third wall is wider and contains a chimney breast 1.5 m wide and 2 m high, the fire place is 0.9 m deep. The walls are constructed of split slate slabs with evidence for lime mortar bonding in places. There is evidence for slate slab flooring within the building. The entrance is at the south east corner where the remains of a short internal piece of wall suggest that there was a small entrance lobby. The nature of the building suggests it is a "Caban", a shelter or mess room for the miners. Methodology: 30 m transect survey. Positional accuracy: less than 10 m. Tolerance of accuracy: +/- 5m. K. Laws, EAS Ltd, 22/11/2007.