Watchtower at Fonmon Castle

The Watchtower at Fonmon Castle is a Grade II* listed structure built from local roughly coursed limestone rubble, with some parts lime-plastered and others rendered. This tall, narrow rectangular tower features a battered base and stands four storeys high, although it is built into the bank, resulting in only the first floor having an additional under-storey.

On the land side (north), the first floor has a modern square-headed opening. The second floor contains a pointed arch door leading into the dovecot, along with a slit vent on the right and another at the rear. There is a c.2000 oak window with a lintel above on the north side for the doves, and the original construction includes a blocked window above the slit vent that illuminated the third floor. An additional room is located above this level. The tower features machicolations on the long walls, a square-headed window on the north, a two-light window on the west, and blind windows on the east and south sides. The tower has a castellated parapet, but the roof is missing.

The interior was not available for resurvey, but it is reported to be largely featureless, except for a central wall that remains in place and the remnants of good quality lime plaster in the topmost room.