The Round Tower at Old Kilcullen is about 10m high and it has a round-headed doorway. This is less than 2m above ground level and about 1.7m high.
Ancient history books such as the Annals of the Four Masters tell of terrible Danish attacks on Kilcullen in 936 and 944 AD. This probably led to the construction of the Round Tower.
The tower is approximately 40 ft high and the top parts suffered a lot in 1798. An account written in 1782 tells of there being four large windows in the upper part of the tower but only the semblance of one now remains. There was a battle nearby on 24th May.