Tucked away in a remote corner of the Erne River system, on a tiny island in Lough Oughter, stands the ruined circular tower of Cloughoughter, a modestly sized castle, with a surprisingly colourful history. It was probably begun by William Gorm de Lacy between 1200 and 1224, possibly on the site of a crannog, after the Normans seized parts of the O'Rourke kingdom of Breifne. The lower two storeys can be ascribed to this phase, it had loops but no entrance on the ground floor, three doorways and at least two windows at first floor level and possibly a curtain wall on the west side.