For the 4 islands in Manila Bay that used to be the Manila Bay Defense Forts, Corregidor-Ft. Mills, Caballo-Ft. Hughes, Fraile-Ft. Drum, Carabao-Ft.Frank.
Zo624. This is the gate to Philippine Insular Government Vault in Fort Mills, on Corregidor Island before the war. My friend fots2 is another great contributor to the Corregidor forum and provided this picture which is also posted in the above URL which I repeat here:
https://corregidor.proboards.com/thread/1002/corregidor-myths-legends?page=4