Its in Montalban (Rodrigue) Rizal. In 1990's these are the japs marker that I personally saw.
1) JAPS CAVE MARKER (Lapida)
2) HUGE SKULL BOULDER (house size).....my TH friend recovered a 1 foot tall bronze budha head from the skull eye socket and sold to Israeli treas hunter.
3) SMALL BUDHA FACE ( human size) carved on the cliffwall near the river.
4) 5 ft tall BIG BUDHA FACE carved on top of the cliffwall.
Meaning there are 2 budha faces, they are facing each other (magkabilang cliffwall) one is on the top (big budha), while the other one (small budha) is in near the river below.
5) RECTANGULAR HOLES/CARvING (ammo box size) on top of several boulders.
6) 3-5 ft ROUND CLOCK ( 10 AM) carved on top of cliffwall.
7) 15 ft tall, MAN MADE BOULDER composed of rock, gravel and cement, totally different from surrounding boulders which is made of solid granite or limestone..
12 inches TRAIN RAILINGS (riles ng train), embedded inside tunnel ceiling.
9) Several REBARS (Kabilya) embedded inside tunnel ceiling, pointing to different directions.
10) 6 inches diameter RUSTY METAL TUBE protruding along the cliffwall near the river.
11) Several old CABLES protruding or embedded from the cliffwall
12) DIGGING SOUVENIRS...japs rifle, samurai, ammos , bombs, medicine ampules, stainless ball (basketball size), and other japs military junks or garbage...
13) OTHER UNDEFINED ROCK CARVINGS....
These are the Japs markers that my TH team had seen, am sure most of them are still there specially the bigger ones or at the top of the cliff....some of them probably had a house built on top of it or covering it.