Round towers are mostly found in Ireland and Scotland, where they were built as a means of defense against Viking raiders. A lookout was posted at the top of the tower; when a Viking longboat was spotted, the local population would enter the tower, using a ladder which would be raised from within. The towers were also used to store religious relics, and other plunderables.
A famous example of a round tower is at Devenish, an island on Lough Erne in County Fermanagh, Northern Ireland.
Devenish was a monastic settlement connected with Saint Molaise.
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