Gunung Boleng

Information

Elevation

1.659 m

Country

Indonesia (ID)

Location / Range

Solor Islands, East Nusa Tenggara

Mountain type

Stratovolcano

Volcanic?

Yes — volcano

Coordinates

-1.2520, 100.8006

Difficulty

Hard

Best Season

April–September (dry season)

Permits & Rules

No official permit system; using a local guide from the nearest village is recommended

Hazards

Very steep slopes (50–55°) near the summit; loose pyroclastic material that is slippery when wet; active volcano with 15+ recorded eruptions since 1885; last eruption in 1991

Description

Gunung Boleng (also known as Ili Boleng or Gunung Ili Boleng) is an active 1,659-metre stratovolcano at the southeastern tip of Adonara Island in East Flores Regency, East Nusa Tenggara. The only active volcano on the island and one of the most prolific in the Solor Archipelago, it has produced over 15 recorded eruptions since September 1885 — including the sole historical lava flow in 1888 — and last erupted in 1991. Multiple overlapping summit craters give the peak an irregular silhouette. Three hiking routes serve the mountain: from Kampung Dua/Nisakarang in the north-northeast (approximately 5 hours), from Kampung Lamahelan in the south (approximately 6 hours from the upper village), and from Kampung Lamabayung in the east (approximately 6 hours). The crux near the summit involves slopes of 50–55° over loose pyroclastic deposits that turn dangerously slippery when wet. The nearest town is Wai Werang, reached by ferry from Larantuka on the Flores mainland. The dry season (April–September) is the recommended climbing window.