Crehan Island (Críochán) was once part of the large Fermanagh estate of the Butler family, the Earls of Lanesborough.  The Griffith’s Valuation of 1848-64 lists the owner as Henry Cavendish Butler, the 8th Earl.  In addition to Crehan Island, the estate included the neighbouring islands of Inish Rath and Dernish. 

Cavendish Butler built a fine Victorian mansion house on Inish Rath, now a Hare Krisha Temple. Dernish in now uninhabited, but the 1911 Census of Ireland indicates that it was home to 3 families of tenant farmers. In contrast, Crehan Island has never been inhabited and consequently has thrived as a nature reserve.

Crehan extends to six-acre with a small woodland of mature oaks, scotch pine and beech trees rising from the northwest elevated shoreline.  Falling away from the wood to the southeast, is a large water meadow leading down to a sheltered bay. On the southeast shore there is a solid wooden jetty, providing a safe harbour for a 12-metre sailboat or motor cruiser.

During the summer months with lower water levels, the adjoining larger 100-acre Dernish Island can be reached via a boundary gate leading along a stone causeway. Dernish is seasonally home to the Kettyle herd of pedigree beef cattle, their low intensity grazing recognised as the most effective way of maintaining this specially recognised and protected environment.  

Crehan is easily accessible by boat from both Derryadd and Geaglum Quays and Lisnaskea boat club.  A short drive away from Derryadd Quay is the busy market town of Lisnaskea, with the County town of Enniskillen just 45 minutes away.  Crehan is around a 2-hour drive travelling West from Belfast or North-west from Dublin. 

Today Crehan is managed as a private nature reserve.