Garn fawr or Castell Waunllanau is a motte with a base circumferenec of 152.4m and a diameter of 27m at the top. There is a basin-shaped indentation on the summit.

The mound, which is 6m high, has a well-preserved ditch but no bailey and no trace of masonry.

Source: Ordnance Survey 1966.

The motte is strategically positioned at the head of a south-facing valley.

RCAHMW, August 2023