Thorne Island, a privately owned rocky island of around 2.49 acres in size, situated 3 nautical miles off the coast of Pembrokeshire in west Wales, has been placed on the market for offers exceeding £3 million (€3.5 million), according to the listing on the Strutt & Parker website.
Offering not just sweeping sea views but a fully restored 19th-century fort equipped with modern luxuries, Thorne Island boasts a mid-Victorian citadel that was built between 1852 and 1854 as one of Palmerston’s Haven defences to guard Milford Haven Waterway from Napoleonic attack. The fortress was initially sold in 1932 and has been used as both a hotel and a private residence.
Among its standout features are a helipad for quick access, a covered rooftop bar with a games room for entertaining, and a sea-view office perched high above the surrounding waters. The property combines the rugged character of its historic military architecture with the convenience and style of modern living, framed by the wild beauty of the Pembrokeshire coast.
Now registered as a “Hotel & Premises” for business rates purposes, the property offers flexible potential, from private retreat to boutique hospitality.
Tech entrepreneur Mike Conner, former CEO of Appsbroker, acquired the once-derelict fort in 2017 for approximately £500,000, inspired by a YouTube video. Over the past eight years, he invested around £2 million into restoring and reinventing the site as a self-contained, off-grid sanctuary. “There was a lot of stuff that needed to be done to make it happen,” he said to CNN.
The renovation included installing renewable energy systems such as solar panels, a 100 kWh battery storage, heating, a running drinking water system, modern plumbing with full water-flush facilities, and a biodigester sewage treatment plant, making it entirely self-sufficient.
Logistical challenges included 350 helicopter trips over two days to deliver building materials, and rust-covered walls were sandblasted for six months to reveal original stone. Meanwhile, builders lived on site in the fort’s barracks for four years to complete the reconstruction.
The restored fortress now offers around 8,000 square feet of living space that can accommodate up to 20 people. It includes five bedrooms, grand dining rooms, and terraces with barrack-style walls. Common areas reveal original brickwork and vaulted ceilings, while a rooftop bar and games area crown the structure with panoramic coastal views. Access to Thorne Island is by boat or helicopter, with the property featuring a private jetty, helipad, and multiple moorings.
Set within the Pembrokeshire Coast National Park and designated as a Site of Special Scientific Interest and Special Area of Conservation, the island is surrounded by sandy beaches, rocky cliffs, caves, popular fishing spots and water sports areas. The estate agents describe it as “an adventurer’s paradise,” offering seclusion and sweeping scenic beauty.
Reflecting on the surreal island isolation and creative work done over the years, Conner, who holds a degree in industrial design, described the project as a personal challenge he was eager to take on. “It was quite a healthy mid-life crisis by some of my friends’ standards,” he said.
The island remains ideal for someone looking for a dramatic, luxurious yet secluded space or wants a unique, unconventional hospitality venture to be open to the public.
