Mount Semeru is a volcano situated on the Indonesian island of Java. With an elevation of 3,676 m (12,060 ft), Semeru is the tallest mountain on the island; it is also one of the most active volcanoes in Indonesia. The volcano ejects an enormous cloud of smoke, steam, ash and stones approximately every 20 minutes during particular seasons.
Semeru can be climbed, but it is often closed due to such volatile volcanic activity. In order to climb Mount Semeru, one must first obtain a permit. From the base camp in the village of Ranu Pane, the return journey to the summit of Semeru takes four days.
It is a very steep climb and the terrain is challenging, not least because the highly active volcano presents a unique set of difficulties. Only well-prepared and experienced mountaineers should make the journey, and always heed the advice of local experts.