Carrigafoyle has had a stormy history and, although wrecked by a series of bloody sieges, remains a remarkable castle. Cleverly located between the high- and low-water marks on the shore of the Shannon estuary, it comprises a large tower built towards the end of the 15th century by the O'Connors. The tower was protected on the landward side by two square bawns; these extended into the water and enclosed a small dock, so that boats could sail right up to the castle - a rather useful if not unique feature.The tower has five storeys rising to a height of 86 feet and is beautifully constructed of specially selected small stones laid in neat courses. In 1580 Sir William Pelham besieged the castle, held by the Earl of Desmond, with fifty Irishmen and sixteen Spaniards. Pelham used artillery brought by sea and within two days had battered down the bawn and the landward side of the castle. All the surviving members of the garrison were hung and the Earl of Desmond's plate, stored in the castle, was sent to Queen Elizabeth I. The castle was later recovered by the O'Connors, only to be surrendered again to Sir George Carew in 1600. It is known to have had a garrison of forty men in 1659 to protect the south shore of the Shannon. Despite its wrecked condition the castle was occupied in the last century by a Dr Fitzmaurice and his family.
3 km (2 miles) N of Ballylongford in the channel between the mainland and Carrig Island. Accessible from the road across a raised path of stones liable to be submerged at very high tides. NGR: Q 988474.