It is not uncommon, in those jungles, to find artifacts left over from WWII. I know people living in quonsets huts left by the US. If a new area is being built upon, a wise person always checks for ordnance and other items.
The Japanese were horrific.
“If a new area is being built upon, a wise person always checks for ordnance and other items.”
In 1975, I visited Corregidor. We were strongly advised to stick to the established trails.