
Portland Castle was built in 1539–40 on the orders of Henry VIII as part of his coastal defence scheme, paired with Sandsfoot Castle to guard the important anchorage of Portland Roads on the Dorset coast. The fortress features an unusual fan-shaped design built of local Portland stone and remains almost perfectly preserved. Its distinctive architecture includes a thick-walled octagonal gun block at the centre with an octagonal great hall, gunner's accommodation and kitchen on the ground floor, and officer's lodging above. The castle saw military action during the English Civil War, changing hands between Royalist and Parliamentary forces, and served coastal defence until 1816, with renewed military roles during both world wars. Highlights for visitors include the Tudor kitchen, armoury, gun platform, and a restored governor's garden designed in 2002.