Mount Rinjani

Mount Rinjani rises to 3,726 metres on the island of Lombok, the second-highest volcano in Indonesia, and its summit trek is one of the great walks of Southeast Asia. The reward at the crater rim is extraordinary: a vast caldera holding the crescent lake of Segara Anak, a deep blue-green sheet of water from which a new active cone, Gunung Baru, has grown and still smokes. Hot springs bubble at the lake's edge, and the climb to the true summit, usually tackled before dawn on loose volcanic scree, delivers a sunrise over Lombok, Bali and the sea. The mountain is sacred to the Sasak and Balinese, who make pilgrimages to the lake. It is a serious undertaking, cold, steep and long, almost always done over two or three days with a guide and porters, and it is closed in the wet season.

What you actually see

• The crater rim - the first view down to Segara Anak lake and the caldera.
• Segara Anak and Gunung Baru - the crescent lake and the smoking new cone within it.
• The summit sunrise - the pre-dawn scramble up scree for the view over three islands.
• The hot springs - the warm pools at the lake's edge, a reward on the trek.

When to go

April to November is the dry season and the only time the mountain is open; it closes during the rains, roughly December to March, and around Nyepi. Even in the dry season the summit night is bitterly cold. The trek is timed so the summit push starts hours before dawn.

Honest expectations

This is a genuinely hard, cold, multi-day mountain trek, not a day hike: the summit scree is exhausting, altitude can affect people, and nights on the rim are freezing, so fitness and proper gear matter. It must be done with a licensed guide and porters, and choosing a reputable operator affects both safety and the porters' welfare. The mountain closes entirely in the wet season and can shut at short notice for volcanic activity.

Nearby

The Gili Islands and the beaches of Lombok are reached from the same coast; Bali is a short flight or ferry away.