Trekking in Ijen

East Java is one of the most volcanically active places on earth, and this trip strings two of its set-pieces together over a handful of days. The first is Ijen, whose signature is visible only in the dark: electric-blue flames where sulphuric gas ignites as it escapes the crater. You walk down into the crater at around two in the morning, gas mask on, alongside miners carrying eighty-kilo baskets of raw sulphur up on their shoulders — a working mine, not a show.

The second is Bromo, at the other end of the same day: a small ash cone smoking in the middle of a vast caldera, best seen at sunrise from the rim above as light floods the sand sea around it. The pairing — the underworld at night, the postcard at dawn — is the trip.

Ijen's crater floor closes on gas readings, sometimes for weeks at a time, and masks and guides are required down there. Check conditions before you travel.

A few days chaining two of East Java's volcanic set-pieces.

Ijen is the night piece: you walk down into the crater around two in the morning, gas mask on, to see the electric-blue flames where sulphuric gas ignites as it escapes — sharing the path with miners hauling eighty-kilo baskets of raw sulphur, since this is a working mine, not a show.

Bromo is the dawn counterpart: a small ash cone smoking inside a vast caldera, seen at sunrise from the rim as light floods the sand sea. Expect very early starts, sulphur fumes, and cold pre-dawn air on the climbs.

Go in the dry season, roughly May to September, when trails and skies are most reliable, and use a guide — required on the Ijen crater floor along with a gas mask, both of which operators supply.

The crater closes on high gas readings, sometimes for weeks at a stretch, so check current conditions before you travel and keep the itinerary flexible. Most trips base around Banyuwangi for Ijen and Cemoro Lawang for Bromo, with 2 a.m. departures for each summit.

Bring warm layers for the pre-dawn cold and a buff or mask for the fumes. Book the pairing as a multi-day tour.