"Athenry" < "Béal Átha an Rí" = The mouth of the king's ford (not fort). There may be another such name in Ulster, but it's certainly not a well-known one. But then, there is another Belfast < Béal Feirste other than the one in Co. Antrim/Down and it is on the west coast of the Currán Peninsula in Mayo looking across at Acaill. Not a lot of people know that, to coin a phrase :-)
Annraoi