The Borneo Caverns feature in Uncharted 2: Among Thieves. Located high up in a mountain, the caverns were last occupied by Marco Polo's crew, who had drank the resin.
Events in Uncharted 2: Among Thieves
After searching through Marco Polo's journals, Nathan Drake realises that they must head up to higher ground. Higher up, Drake, Sully and Chloe discover some fairly small underground caverns. They find blue resin, which they use to light the way, and the Phurba dagger inside.
The caverns consist of three main rooms. One is the largest, which is littered with blood and human skeletons. The second is filled with barrels that contain blue resin. The third is concealed behind a damaged wall and contains the Phurba.