Kildare Castle, Medieval castle ruins in Kildare, Ireland

Kildare Castle is a medieval ruin that survives today primarily as a single stone tower standing in the town center. The structure displays the solid construction methods typical of 12th-century defensive buildings.

The castle was founded in the 12th century by Richard de Clare, the 2nd Earl of Pembroke, as part of Anglo-Norman expansion into Ireland. It originally operated as a motte and bailey fortification, a common defensive design of that period.

The castle served for centuries as a symbol of Anglo-Norman power in the region, shaping Kildare's identity across generations. Today, the tower reminds visitors of an era when such fortifications formed the center of community life.

The ruin sits in an accessible location within the town center where visitors can examine it from the outside at any time. Wearing sturdy shoes is recommended, as the ground around the structure can be uneven.

Kildare Castle was besieged without success by Edward Bruce in the winter of 1315–1316. In 1294 O'Connor Faly raided the castle and town, taking money, cloth, supplies and livestock worth £1,000. The surviving tower dates from the 13th century and was probably converted into a residential tower in the 15th century.