Extract from the bronchure for the Mulu National Park, Sarawak, Malaysia by Sarawak Tourism Board :

"The famous Pinnacles at Mulu consist of a series of 45 metre high, razor-sharp limestone spikes that tower above the surrounding vegetation, mid-way up the slopes of Gunung Api. The trek to view them is one of the most popular in the park. But be warned, the Pinnacles Summit Trek is a tough and challenging one. The trail itself is very steep and requires a certain level of fitness. The trail is 2.4km in length but rises some ... (more)