Portland Castle is an artillery fort in United Kingdom

Portland Castle is an artillery fort constructed by Henry VIII on the Isle of Portland, Dorset, between 1539 and 1541. It formed part of the King's Device program to protect against invasion from France and the Holy Roman Empire and defended the Portland Roads anchorage. The fan-shaped castle was built from Portland stone, with a curved central tower and a gun battery, flanked by two angular wings. Shortly after its construction, it was armed with eleven artillery pieces, intended for use against enemy shipping, operating in partnership with its sister castle of Sandsfoot on the other side of the anchorage. During the English Civil War, Portland was taken by the Royalist supporters of King Charles I, and then survived two sieges before finally surrendering to Parliament in 1646.

Thanks and credit to Google Earth Studio for this aerial video.