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.
Ze069. This is the 2nd concrete structure in the smaller, east creek/ravine contributing into the James Ravine. This is by Road Junction 93 of the Abbott Trail/Road and near the pillbox most of us are familiar with.
Ze065.-12 image of the discharge side of the upper 4 foot culvert under the James Trail/Road near the Abbott Trail intersection 93. For your orientation the pillbox is shown.
Ze061.-07 shows the intake side of the first upstream culvert, this side stream to the James Ravine runs under the James Ravine Road twice next to that pillbox we are all familiar with.