In the angle of the walls. difficult to photograph. Juvenile?
This frog was at least 6m from the floor of the cave and well into the dark part of the cave. Unlike https://www.inaturalist.org/observations/203784963, which was wedged into a crack in the wall, this frog was on a flat wall. A very shallow stream emerges from the back of the cave and runs towards the entrance near where the frog was found. Its possible that the frog was washed into the cave, but I suspect it climbed the wall from the entrance floor.
Frog is small, approximately 3cm.
This frog was in the twilight zone of the cave approx 2.5m from the ground. The frog had wedged itself into a crack and seemed quite happy on the near vertical wall.