On les trouve en Europe du Nord, en particulier en Irlande. En langue irlandaise, ils sont connus sous plusieurs noms : rÃ th -LRB- anglicised rath -RRB-, lios -LRB- anglicised lis -RRB-, caiseal -LRB- anglicised cashel -RRB-, cathair -LRB- anglicised caher or cahir -RRB- and dÃ n -LRB- anglicised dun or doon -RRB-.
A rÃ th -LRB- anglicised rath -RRB-, was made of earth, caiseal -LRB- northwestern Ireland, anglicised cashel -RRB- and cathair -LRB- southwestern Ireland -RRB- were built of stone.