Aik Kalak hot springs.

Tucked onto the volcanic flanks of Mount Rinjani, Aik Kalak is a geothermal hot spring that offers a dramatic transition from cool highland air to steaming, mineral-rich pools. Located just 200 meters from the trekking basecamp, this open-air basin is naturally heated to around 45°C by the active volcano above, making it a favored recovery ritual for hikers looking to soothe tired muscles. Beyond its physical appeal, the site holds deep spiritual significance for the local Sasak people, who consider the waters sacred. Visitors might witness traditional rituals here, including the washing of heirloom weapons, while others come for the sulfur-rich waters, long believed to have therapeutic benefits. It is a rare mountain stopover where natural therapy and living culture meet.