Kawah Ijen

Kawah Ijen is one of the world's most extraordinary natural phenomena. Located in East Java near the border with Bali, this volcanic complex contains the world's largest acidic crater lake (pH 0.5) — a spectacular turquoise pool surrounded by yellow sulfur deposits.

The main attraction, which puts Ijen on every photographer's bucket list, is the famous blue fire (Api Biru) — a natural phenomenon where sulfuric gases combust as they emerge from the crater vents, creating electric blue flames visible only in the dark hours before dawn.

Visitors also witness the arduous work of the sulfur miners, who carry loads of up to 90kg of sulfur up the steep 3km trail from the crater, often without protective equipment.