Horse Island, County Cork

In the 19th century, a copper mine was operated^[6] on the 157 acre island by West Cork Mining Company, owned most recently by West Cork Mining Company,^[7] employing approximately 100 miners at one time. The mine started operating in 1820 and closed in 1874.^[8][9] At its peak in 1841, the island's population was 137. The last permanent resident, Paddy McCarthy, left Horse Island in 1965. In his time, there were only five families on the island.^[10][11] Willie Harcourt-Cooze's father bought Horse Island, where he started farming and living a self-sufficient life.^[12][13]

For some years, the island was owned by Gert Kölbel, a wealthy German (inventor of the Bullworker),^[14] who renovated a few of the buildings in the 1980s. It was sold to financier Adrian Fitzgibbon and wife Deborah in 2007. In less than a year, they turned a barn into the main house.^[15] By the time they listed it for sale in 2018, "The island has seven houses, including a six-bedroom main home, plus a pier, helipad, gym, tennis court ... its own electricity, water and sewage systems" according to The Guardian.^[16] Another source added that the island also included "six guesthouses and guest cottages", three diesel generators, wind turbines" and pipes to an underwater aquifer for drinking water.^[17]

In 2014, an attempt had been made by the Fitzgibbon family to set up an Irish whiskey distillery and visitor centre on the island, but planning permission was refused by An Bord Pleanála.^[18][19] The couple had also attempted to raise Wagyu cattle but that plan did not work successfully.^[20] The island still had a "main cattle shed, an implement shed [and a] workshop" as of 2019.^[21]

As of June 2018, the island had a permanent caretaker.^[22]