There is something rather attractive about round tower houses, but sadly only a relatively small number were built, mostly in Munster. Perhaps the finest to survive is the impressive early 16th century tower of the Purcells at Ballynahow.
Ballynahow Castle stands five storeys high with two internal vaults, each covering two storeys; the top storey was for merly covered by a conical timber roof carried on squinch arches. Both the lower floors were dimly lit round chambers that were probably used for storage, though their size was relatively small because of the wall's thickness at this level. The three storeys above were larger and approximated to a rectangular shape, with ogival and segmental headed windows.