Back in 1939, researchers Davies and Swan believed they’d found the remains of Fahan Castle in a field near Castletown Cottage, spotting what appeared to be foundations visible through growing corn. However, the true location of this medieval stronghold remains elusive, with no definitive traces surviving above ground today.

Later archaeological surveys by the Donegal Survey team found no visible evidence of castle features at the site Davies and Swan had identified, though the landowner did unearth some tantalising stones and bricks whilst cultivating a corner of the north field adjacent to the farmyard. These fragments hint at something substantial once standing here, but whether it was the castle itself or another structure remains unclear.

Current archaeological thinking suggests that Castletown House, situated 400 metres south of Castletown Cottage, offers a more convincing candidate for the medieval castle’s location. This site contains both the castle remains (catalogued as DG038-023) and an associated bawn, a fortified enclosure typical of Irish castles (DG028-023001). The bawn would have provided additional defence for the castle’s inhabitants and their livestock, forming part of a larger defensive complex that once dominated this portion of the Donegal landscape.