Mount Rinjani rises 3,726 metres above Lombok, its caldera carved by a collapse 13,000 years ago that left a six-kilometre-wide basin now cradling Segara Anak, a crescent lake 600 metres below the summit.
The Sasak people regard the peak as sacred, and pilgrims still ascend its flanks to leave offerings at hot springs bubbling from the crater floor. The volcano last erupted in 2016, scattering ash across East Lombok and closing trails for eight months while forestry teams rebuilt footbridges and cleared rockfall from the Sembalun and Senaru routes.
Mount Rinjani tour packages typically follow the Sembalun ascent, a route that trades gentler gradients for longer exposure above the treeline. Trekkers register at the conservation gate in Sembalun village, where the 250,000-rupiah daily fee funds trail maintenance and ranger patrols across the 41,330-hectare Gunung Rinjani National Park. From the gate at 1,156 metres, the path climbs through cassava farms and savanna grassland, reaching Pos II shelter at 2,000 metres within three hours. Most groups camp at Sembalun Crater Rim (2,639 metres) on night one, waking at 02:00 for the summit push. The final 1,087-metre ascent crosses loose volcanic scree; headlamps trace slow-moving chains of light up the ridgeline in the hours before dawn.
The summit stands above the cloud layer on clear mornings, with Lombok's southern coastline visible 40 kilometres to the south and Bali's Mount Agung breaking the western horizon. Crater rim camps look directly down onto Segara Anak, where sulphur vents stain the lake's north shore yellow and steam rises in vertical columns. Three-day itineraries descend into the caldera on day two, crossing the crater floor to bathe in the 60-degree springs before climbing out via the Senaru trail, a steeper exit through montane forest thick with orchids and edelweiss. The national park enforces a 15:00 gate closure for new arrivals, ensuring trekkers reach Crater Rim before nightfall. Guides carry satellite phones, and porters ferry tents, sleeping bags, and propane stoves up the mountain in woven baskets strapped to wooden frames. The conservation fee has funded six aid posts along the trails since 2019, each stocked with oxygen and radio links to the ranger station in Sembalun.
48 hr
