From a distance, Gunung Rinjani (3726m) appears to rise in solitary glory from the plains, but in fact the entire area is a throng of bare summits, wreathed in dense forest. The climb up Rinjani, taking in Danau Segara Anak, the magnificent crater-lake, with the perfect cone of Gunung Baru rising from it, is the most energetic and rewarding trek on either Bali or Lombok. Climbs start from either Senaru to the north of the mountain or Sembalun Lawang to the northeast.
Trekking on Rinjani is not for the unfit. A guide is essential and you must register at the Rinjani Trek Centres at Senaru or Sembalun Lawang and pay the National Park admission fee (whttp://www.rinjaninationalpark.com). You’ll need basic equipment; bring your own walking boots, a torch and food and drink (take loads of snacks and sweets even if food is provided). If you haven’t got a seriously warm, windproof jacket with you, rent one. The Rinjani Trek Centres rent out radios but increasingly mobile telephones are being relied on as emergency back up; make sure your party has one or the other.