Today, only two short sections of wall footings survive the centuries and the extensive gravel quarrying that has reshaped this low hill. The southern wall fragment stretches just 4 metres, whilst the northwest corner reveals what may have been part of a rectangular structure, though the 20th-century antiquarian Westropp noted traces of what could have been a side turret. The western wall once stood atop a steep drop, and chunks of bonded masonry lying downslope suggest it reached about 3 metres in height until recently demolished by a local farmer. The interior area, measuring roughly 8 metres square, sits noticeably lower than the surrounding ground level; a depression that might mark the remains of a ground-floor vaulted chamber, particularly as vaults were reportedly discovered beneath the site by a former landowner.

This castle, variously known as Gortadroma, Monymohill, and Moyreen Castle, has a documented history stretching back to at least 1289, when the lands of Moyreyne were granted to Robert Maunsel. By the 16th century, it had become embroiled in the tumultuous politics of Tudor Ireland. The Desmond Survey describes it as belonging to Hugh Wale, alias Falltaghe, “a rebel attainted by judgment of High treason”, before being leased to Oliver Stephenson in 1582. Unlike the nearby great castle of Donmoylin with its stone-walled enclosure and various buildings, Monymohill was already described as ruinous by 1583 and appears never to have been repaired, vanishing from mention in the Civil Survey. The 1658 Down Survey map depicts it as a tower-like castle, one of the last visual records before time and quarrying reduced it to its current state.

The castle’s ownership passed through various hands over the centuries; from the Stephenson family in the early 1600s to Brook Bridges and J. Bourke in 1655, then to Oliver Lambert in 1665. It was forfeited by N. Burke in 1688, and by 1726, Robert Morgan of Connegarr was mortgaging parts of the Monymohill lands. Though the walls reportedly still stood in 1840, today’s visitor will find only these modest footings, a far cry from the defensive structure that once commanded this strategic position over the White River valley.