El Fraile Island

Fort Drum, is a heavily fortified island situated at the mouth of Manila Bay in the Philippines, due south of Corregidor Island. The reinforced concrete sea fort, shaped like a battleship, was built by the United States in 1909 as one of the harbor defenses at the wider South Channel entrance to the Bay during the American colonial period.

It was unique among forts built by the United States between the American Civil War and early World War II, as it was a sea fort with turrets. It was captured and occupied by the Japanese during World War II, and was recaptured after U.S. forces ignited petroleum and gasoline in the fort, the conflagration killing 68 Japanese soldiers and leaving it permanently out of commission. It was five days before U.S. soldiers could enter the fortress because of the heat.