The Batu Bora mountain range is a sandstone range lying between the Plieran river and the great Usun Apau Plateau to the north, or about 3.5 kilometers from the Plieran river to the south. The main Batu Bora mountain is 1,500m high and dominates the upper Plieran valley. The mountain forms a great massif. While in the south-east of the range is the secondary formation of Mudung Batu Bora, a great ridge 1,300m high with a series of jagged rocks sticking out along the top like teeth. Mudung or Bukit Batu Bora is also known by the Kenyah name as Mudung Bora, which refers to white (white as cotton) with low clouds hanging over the mountain. A day-trip climbs to the 1,500m Mudung Bora summit can be organized and the old route will give climbers a taste of the Plieran Range terrain to offer a great challenge for mountain climbing enthusiasts. It is possible to climb Mudung Batu Bora, but this is for a planned expedition, experience guides, mountaineering gears and a few porters will be needed.