Fort Drum (Philippines)

Fort Drum, also known as El Fraile Island (Tagalog: Pulo ng El Fraile), is a heavily fortified island situated at the mouth of Manila Bay in the Philippines, due south of Corregidor Island. Nicknamed a "concrete battleship", 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. Due to the high temperature caused by the conflagration it took five days before U.S. soldiers could enter the fortress.

The now-abandoned fort was named after Brigadier General Richard C. Drum, who served with distinction during the Mexican–American War and the American Civil War, and died on October 15, 1909, the year of the fort's construction. The island and the other former harbor defenses of Manila Bay fall under the jurisdiction of Cavite City.