[2][3][4] Carabao Island is located near the southern end of the entrance to Manila Bay about 0.5 miles (0.80 km) off the coast of Maragondon in the province of Cavite.

[3] The establishment of the islands of Manila Bay as military reservations was requested by the US Army and enacted by Executive Order of President Theodore Roosevelt on 11 April 1902.

Also, most of its heavy ammunition was armor-piercing, intended for use against battleships, rather than the high explosive type that would be more useful against enemy troops and artillery.

On 31 January 1942 the fort's mortar battery bombarded mainland positions in the Pico de Loro Hills that the Japanese were emplacing artillery in.

Although the fort also had a distillation plant to provide fresh water, this consumed fuel that was also needed for the gun batteries' generators that powered the ammunition hoists.

The fort's commander ordered the distillation plant started, but also directed a 15-man team to attempt to restore the pipeline on the 19th.

In April 1945, during the American liberation of the Philippines, Fort Frank was heavily bombarded with 1,000 lb (450 kg) bombs and napalm (among other ordnance) in preparation for recapture.