Batu Caves Introduction: Batu Caves is a limestone cave that covers several caves, mainly light caves and black holes. The black hole is more than 2 kilometers long. The cave is dark and cool, and the trails are winding. The light hole is next to the black hole, 50 meters high and 70 meters wide. Sunlight can enter from the hole on the top of the cave, and the light makes the cave confusing.