Thorne Island

Thorne Island is a small rocky islet in Pembrokeshire, Wales. It lies at the entrance to Milford Haven Waterway and covers just two acres. The island is dominated by a 19th-century coastal artillery fort built to protect the anchorage and nearby Pembroke Dock. Its position made it a key part of a wider defence system around the haven. The fort was planned after fears grew of a French naval threat in the 1850s. Work began after 1852, and the date 1854 is carved above the entrance. The fort was designed to house heavy guns facing the sea. It had five 7-inch Armstrong guns and four 68-pounder guns mounted on open parapets. The landward side included a defensible barracks with loopholed walls. In 1860, a Royal Commission report found the fort could not stop fast warships. This led to more forts being built around the haven. Thorne Island’s role was limited but it remains a well-preserved example of Palmerston’s coastal defences. Today the island holds a restored fort that once became a hotel in 1947. It was later a Grade II* listed building and changed hands several times. The latest owner has spent years returning the fort to a habitable state. Divers visit the surrounding waters to explore over twelve wrecks. One famous wreck is the Loch Shiel, which sank in 1894 carrying whisky and beer. Some recovered bottles still fetch high prices at auction.