Gunung Rinjani

Mount Rinjani National Park was established in 1990 on the island of Lombok, in West Nusa Tenggara, and protects some 413 km² around the Rinjani volcano, which at 3,726 metres is the second highest in Indonesia.

Its defining element is the Segara Anak caldera, a depression some six by eight kilometres formed by the collapse of the volcanic edifice, occupied by a turquoise lake at an altitude of around 2,000 metres. Within the lake itself an active secondary cone has grown, Barujari, which has erupted several times in recent decades and which forces periodic closures of access to the park. Around it are hot springs whose waters are held to be curative.

The ascent of Rinjani is one of the most popular treks in South-East Asia, with thousands of walkers a year, which generates problems of waste and erosion that management has tried to tackle with quotas and clean-up campaigns. The volcano also carries a strong spiritual charge both for the Sasak, mostly Muslim, and for the Balinese Hindu minority of Lombok, who make offerings at the lake. The vegetation is tiered from tropical forest on the lower slopes to high-altitude savannah and bare volcanic ground. In 2018 UNESCO designated the Rinjani-Lombok Biosphere Reserve.