Investigation Summary
A medieval fortress and OPW National Monument at a strategic Shannon crossing in Athlone, County Westmeath, Ireland. A wooden fortification was established in 1129; the stone castle was built c. 1210.
The site's most significant event is the June 1691 Siege of Athlone, in which approximately 12,000 cannonballs and 600 bombs were fired over ten days — described as the heaviest bombardment in Irish history to that point. Multiple primary sources survive, including a published 1691 Williamite engineer's diary and Captain John Stevens's journal. Medieval exchequer records document construction costs from 1270.
The castle is now an OPW-managed visitor centre with eight permanent exhibition spaces. No paranormal tradition is associated with this location in any source reviewed.