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.
Ze277. My GPS track on a Google earth image from Telephone Hut #3 to the fresh water tank on the Battery Denver Ridge line, Ft. Mills on Corregidor Island.
Ze271. This drawing came from the writing of: WE STORM CORREGIDOR from Jan Valtin and it is presented here by Corregidor.org: http://rockforce.org/valtin/valtin_01.html
By the way, Jan Valtin was a German American.