Isle of Portland

The Isle of Portland is a tied island in Dorset, joined to the mainland by Chesil Beach. It stretches 6 kilometres long and 2.7 kilometres wide, with Portland Bill marking its southern tip. The island sits 8 kilometres south of Weymouth, forming the southernmost point of Dorset. A road crosses the Fleet Lagoon by bridge to reach the mainland. Portland has been inhabited since at least the Mesolithic period, with evidence found at Culverwell Mesolithic Site near Portland Bill. Portland is famous for its high-quality limestone, used in major buildings such as St Paul’s Cathedral and the UN Headquarters. The island’s harbour, one of the world’s largest man-made harbours, was built between 1848 and 1905 as a Royal Navy base. It played key roles in both world wars and later hosted events during the 2012 Olympic Games. Portland Castle, built by Henry VIII in 1539, remains one of the best-preserved coastal forts of its time. Visitors find dramatic cliffs, historic quarries, and coastal views along Chesil Beach. The island’s railway lines, now closed, once carried stone to ships at Castletown pier. Remnants of wartime defences and the former naval air station can still be seen. Portland Bill Lighthouse stands at the southern tip, guiding ships through the English Channel. The low-lying village of Chiswell shows how the island has adapted to coastal flooding risks.