Tung Lung Fort, on the northeastern corner of the island of Tung Lung Chau, was built in the late 17th or early 18th century and was attacked a number of times by pirate bands before being abandoned in 1810. The fort once consisted of 15 guardhouses and was armed with eight cannons, but little of it remains today except for the outline of the exterior walls. There’s an information centre (9am-4pm Wed-Mon) here.