A popular hiking area in East Java, Ijen Crater, part of the Ijen Plateau, is bursting with volcanic activity. Here you can see the largest acidic lake in the world, which by day is shrouded by mists of white smoke and by night crackles with electric-blue flames.
The Ijen Plateau was once a huge active volcano, which can be reached from Banyuwangi, the most easterly city on Java, just across the water from Bali. The area is still mined for its yellow crystalline sulphur deposits and is famous for the bright blue waters of the crater lake. The climb from the bottom to the crater takes approximately 90 minutes along a winding path up the mountain slope. The steepest climb is early on and once you get near the crater rim, the incline does begin to level off. Although not for the faint-hearted, the views over the crater, lake and surrounding hills are well worth the climb.
The area surrounding the crater is East Java at its finest. Forest-clad hills, terraced rice fields and towering mountain peaks provide a beautiful setting for a night or two before or after embarking on the trek up to the crater.