Clondalkin Round Tower is located in the village of Clondalkin in county Dublin. This beautiful 9th century round tower is built on the site of a monastery founded by St Mochua 200 years earlier. It is one of only four remaining in County Dublin, the others are located in Swords, Lusk and Rathmichael. It stands over 90 foot high and is thought to be an early example as the granite on the lintels is flat. The most unusual feature of this tower is the very pronounced buttress at the base which is constructed with a different type of stone to the tower. The series of steps was believed to be added to the buttress in the late 19th century. There are 6 windows in the tower and the top 4 of them point north, south, east and west. The church of St John, on the opposite side of the road, has two early crosses and a granite font from the original monastery and the site of St Brigid’s well is also not far way. The Viking King, Olaf the White, built a fort here in 852 ad. The monastery was plundered in 832 a.d and in 866 a.d.