|Native name Caisleán Bhaile na dTrí Chaisleán|
|Location||Blessington, County Wicklow, Ireland|
Threecastles Castle is a rectangular three-storey tower house, with a stair turret projecting from the north east corner. Originally there was a structure attached to the west side of the tower, as the remnants of a barrel vault are visible. Another vaulted roof is evident on the upper floor. On the first floor has a fireplace and a gardrobe. The walls are four to five feet thick, and are faced with cut granite. The castle sits on an east facing slope overlooking a ford on the River Liffey.
The history of the castle is unclear, but it is believed that due to the castle's name there were more than one castle in the townsland. Of the other two castles, the site of one is known from a 19th-century Ordnance Survey, the third castle's site is unknown. It was probably built by Lord Deputy Gerald Fitzgerald, 8th earl of Kildare, in the 16th century. It was the site of a number of battles in the 1500s. Though some speculate that the three refers to the castle having three parts.
Media related to Threecastles Castle at Wikimedia Commons
- "National Monuments of County Wicklow in State Care" (PDF). National Monument Service. Retrieved 21 June 2015.
- "Threecastles Castle". Irish Antiquities. Retrieved 21 June 2015.
- "Threecastles Castle". Megalithic Ireland. Retrieved 21 June 2015.
- O'Byrne, Emmett (13 July 2011). "Site was scene of bitter fighting, Wicklow History: Three Castles". Wicklow People. Retrieved 21 June 2015.
- "Placenames around Blessington". Blessington.info. Retrieved 21 June 2015.