Doon Hill is a landmark that can be seen from miles away by land or sea. Coming from Galway, the first glimpse can be got, across the bog in Gabhlan, on the hill above Clifden. Fishermen use it as a landmark to guide them into Bunowen Pier. The Irish name dun means fortress possibly indicating that during Celtic times there was a fort on top of the hill. In 1650 the castle and estate was planted by a landlord from Westmeath named Arthur Geoghegan. He inhabited the castle until the year 1840.