Magilligan is a peninsula at the mouth of Lough Foyle in County Londonderry, Northern Ireland. It is an extensive 79,000-acre (32,000-hectare) coastal site, part military firing range and part nature reserve, and is home to HM Prison Magilligan. The tip of the peninsula, which lies less than a mile from Greencastle in County Donegal, is known as Magilligan Point. The two are linked by a ferry service.