This longhouse lies to the east of one of the small streams that join to create the Brefi in Blaen Brefi. It is a three-celled structure, aligned north to south, 15 metres by 5.5 metres. To the south, the lower cell is a drystone fold. The central cell has walls 1.3 metres wide. There are orthostatic stones within the wall bases of the upper cell, which are 0.7 metres wide. J.J. Hall, Trysor, 21st February 2013