I started exploring the 1:2500,000 scale map in NAMRIA website. The site contains treasure trove of information concerning an area. They are old, but some information are relevant.

The box of scale 1:250,000 is made of smaller tiles of scale 1:50,000. It was annoying clicking the box because of the small resolution. I decided to let python script do it for me. I downloaded all the map of resolution 1:50,000.

An example of the map available,

This is a subset of the area of Dapa in Siargao. The small island on the left is the famous Dako Island, compared this with the image below.