The Round Tower may have been built in the tenth century, during the kingship of Brian Boru. His wife was Mor Ni Eidhin from the O'Hynes clan of South Galway.
There is a tradition that it was built by the legendary tradesman, the Goban Saor.
It was used as a Belfry: the bell is supposed to lie at the bottom of a nearby lake.
St. Colman founded the first church in Kilmacduagh c. 610 A.D. As time went on other churches were built there and people were buried in the churchyard.
The Round Tower is built on a burial ground. During renovations by the Board of Works in 1878/9 some tombs were found under the tower. That is probably why it leans. It leans about two feet from the perpendicular. The renovations were carried out at the behest of Sir William Gregory of Coole Park.
The tower is about 120 feet in height. The antiquarian John O'Donovan said in 1838 that it would surely fall within a century
A 17ft. cap was restored in 1878/9. The crack from top to bottom was repaired at that time and a lightning conductor was added. It is believed that the original crack was caused by lightning.
The doorway is c. 26 feet above the ground. The tower's foundation is only about 2 ft. deep.
The walls at the base are 6'5" thick and at door level they are 4'6" thick. They are made of local limestone.
There are now no floors or ladders but originally there were probably seven or eight storeys.
The tower was again repaired in 1971