Semeru

Semeru is an active stratovolcano in East Java and the highest peak on the island of Java at 3,676 metres. It is a prominent feature of Bromo Tengger Semeru National Park and is known locally as Mahameru.

The volcano is frequently active, producing occasional ash plumes and small eruptions from its summit crater; it is monitored by Indonesian volcanological authorities. Climbers and trekkers routinely observe volcanic activity from safe distances while ascending to the crater rim.

Treks typically begin from the village of Ranu Pani and proceed to a high camp area (Kalimati) before a pre-dawn final push to the summit crater to see sunrise and the crater glow. The route includes exposed high-altitude trails and requires appropriate preparation.

Semeru stands within the volcanic highlands of East Java and is part of a national park that also includes the nearby Tengger caldera and Mount Bromo; the surrounding landscape is volcanic plateau, lakes and grassland.

• Elevation and activity: Highest mountain on the island of Java at 3,676 metres and an active stratovolcano with frequent small eruptions and ash plumes.
• Access and approach: Access is through Bromo Tengger Semeru National Park and the standard ascent typically starts from the village of Ranu Pani; summit approaches cross exposed ridges to the crater rim.

What to See #

• Mahameru crater: Mahameru crater - the summit crater at the top of Semeru, which emits frequent small eruptions and gas plumes.
• Ranu Pani / Kalimati approach: Ranu Pani and Kalimati approach - the common trailhead and high camp area used by trekkers ascending the volcano from the southern side.