Antrim Round Tower, Co. Antrim
The tower was built around the 10th century as a bell-tower for protection from raiders and is known locally as The Steeple. It is 28m tall and is one of the finest of its kind in Ireland. The Annals report that the site was destroyed in 1018 and finally burned in 1147. There is an unusual cross carved stone above the lintel and also eight simple, flat headed windows. A large boulder known as the Witch's Stone, with two sizable bullauns, lies approximately 6m from the tower, slightly to the left front of the doorway.
Ardmore Cathedral and Round Tower, Co. Waterford
It is believed to be the oldest Christian settlement in Ireland. St. Declan lived in the region at some time in the period 350-450 AD and christianised the area before the coming of St. Patrick. There is a well-preserved 12th-century Round Tower and the ruins of a Cathedral and oratory dating from the 13th and 8th centuries respectively.
Clonmacnoise, Co. Offaly
Clonmacnoise was founded in 545 by Ciaran (Kieran) of Clonmacnois, one of the 12 Apostles of Ireland. The site includes the ruins of a cathedral, 7 churches (10th-13th century), 2 Round Towers, 3 High Crosses, the largest collection of Early Christian graveslabs and a 13th century castle ruins.
Devenish Island Monastic Site, Round Tower, High Cross and St. Mary's Augustinian Abbey, Co. Fermanagh
It was founded in the 6th century by St Molaise also known as St Laisren (Laserian). During its years of operation the monastery was a site of worship and education. It also shared the work of copying and illuminating important manuscripts with many other Irish monastic communities. The most visible and noteworthy of the remains is a well preserved Round Tower rising 30m high and dating from the 12th century. It is one of the few round towers you may actually climb using an internal ladder. On the hilltop sits St Mary's Augustinian Priory which is of the mid 15th century.
Dromiskin Round Tower and High Cross, Co. Louth
It is a short, round tower, standing just 17m high, with five large bell-storey windows and a two order Romanesque arch doorway. The monastery at the site was believed to be founded by St. Patrick in the 600s. Dromiskin Round Tower was damaged many times: by the Irish in 908, by the Danes in 978 and by the Irish again in 1043.
Glendalough Monastic Site, Round Tower and Valley, Co. Wicklow
It was founded by St. Kevin in the 6th century. Set in a glaciated valley with two lakes, the remains include a superb round tower, stone churches and decorated crosses. The wooded valley contains stunning scenery, way-marked walking trails, if you are lucky you will see some wild deer and goats.
Killala Round Tower, Co. Mayo
This is a well-preserved Round Tower 25m high, standing on a metre high plinth, and with a doorway 3m above the ground. The foundation of the diocese dates from the time of St. Patrick, who placed his disciple St. Muredach over the church called in Irish Cell Alaid.
Kilmacduagh Monastic Site and Round Tower, Co. Galway
This interesting early Christian site is well worth a visit for its ruined churches and well preserved round tower the highest surviving in Ireland (and leaning 0.5m out of perpendicular). The monastery was founded here in the 7th Century by St. Colman MacDuagh.
Rattoo Round Tower and Church Ruins, Co. Kerry
The round tower reaches a height of 28m, with a base circumference of 15m. This is the only complete round tower in Kerry, and possibly dates from the late 10th or early 11th centuries.