Portland Castle lies on the north of the Isle and was built during the 16th century. It has a covered gun platform (Casemate) and a low keep. The casemate presents a semi-circular wall to the sea, with embrasures for 5 guns, while 4 more guns were mounted on the roof. The castle was almost indestructible for the walls were built of the local stone and were 14 feet thick. It cost £4964 18s 10 1/4d.
Both it and Sandsfoot Castle in neighbouring Weymouth saw no action against foreigners, while protecting Portland Harbour from potential attacks.
Click on thumbnails for descriptions and bigger pictures.