Mount Semeru is a volcano on the Indonesian island of Java. It is located to the east of the region, in Bromo Tengger Semeru National Park. The park protects the Tengger Sand Sea (a flat desert with no vegetation) and several mountains and volcanoes. 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.
Mount Semeru’s most remarkable feature is its eruption schedule. 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.
What can grow here is extremely limited by the constant volcanic activity. Above an altitude of 3,100 m (10,171 ft), nothing grows at all. The volcanic ash and other debris do, however, create a fertile soil in which rice fields thrive in lower areas.
In order to climb Mount Semeru, one must first obtain a permit in advance. 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.