Corn Barn at Great Trerhew Farm, Monmouthshire

The barn at Great Trerhew Farm, Llantilio Crossenny is listed Grade II* and is possibly the last barn of this quality remaining in agricultural use in the county, if not in south Wales. The barn dates from the late 16th century.

It seems to have been extended in the late 17th century and now has eight bays with two king-post trusses, gabled additions with cider mill and press, cattle stalls, stable and haylofts with stone chaff bin.

The barn is constructed of rubble stone walling with a slate roof. It has a stone-flagged threshing floor and a lofted cowhouse. The entrance to the cider house is by steps built into the wall on the ground floor.