Trallwyn Hall is an early nineteenth century mansion associated with outbuildings and estate buildings, and set within extensive grounds and gardens (NPRN 86495). An earlier house is represented by a reset stone dated 1602. It is a two storey house with attics and basement. The walls are painted render or stucco, over stone rubble and it has hipped slate roofs. The main garden front faces south, looking out across the valley of the Afon Erch. The ground floor on this side has a loggia with slender Doric columns. The entrance front faces east. This has a five bay facade with a central round headed doorway set within a columned porch. The service courts and buildings are to the west.

Sources: RCAHMW Caernarvonshire Inventory II (1960), 202-3 No. 1257
CADW Listed Buildings Database (4324)

John Wiles, RCAHMW, 31 May 2007