Ballyvaghan Castle, marked on Ordnance Survey maps from 1842 onwards, has completely vanished from the landscape, though its turbulent history lives on in historical records. First mentioned in the O’Brien rental of 1380, the castle began as an O’Loughlin possession before changing hands multiple times over the centuries. A cattle dispute in 1540 saw it pass to the O’Briens, only to be attacked and reduced by Sir Henry Sidney, Queen Elizabeth I’s Deputy, in 1569. The fortress then ping-ponged between various families; the O’Loughlins, O’Connors, O’Briens and Nugents all claimed it at different times.

By 1646, the castle was granted to Christopher O’Brien, suggesting it still stood in some capacity, but by 1837 only “some old vestiges” remained according to contemporary accounts. Today, visitors to the site will find no trace of the medieval structure itself, though several large quay stones stretching about five metres can be spotted six metres west of the promontory. These might be remnants of an old pier or possibly part of the castle’s seaward fortifications, though their exact purpose remains unclear.

The antiquarian Thomas Johnson Westropp, writing in 1901, described this as the site of a “peel tower” that once adjoined a great stone fort or “caher”. While there are indeed remains of a large cashel about 150 metres north-northeast of the castle site, Westropp noted that the tower itself had already “entirely perished” by his time. The castle’s complete disappearance makes it a ghost of Clare’s medieval past; a place where political power, family feuds and military might once converged on this strategic coastal position, now returned to an unremarkable stretch of shoreline.