Mount Bromo

Where it sits. Mount Bromo is a small, constantly steaming cone standing inside a much larger caldera in East Java, about 90 kilometres southeast of Surabaya and 55 kilometres from Malang. Its summit reaches 2,329 metres, which makes it far from the tallest thing in view, but its position is what counts: it rises from the floor of the Tengger caldera, a collapse basin roughly ten kilometres across whose flat floor is covered in fine volcanic ash and known as the Laut Pasir, the Sea of Sand. Bromo shares that floor with the perfectly fluted, extinct cone of Batok and the older stumps of Kursi and Watangan, and behind them all, eight kilometres to the south, stands Semeru at 3,676 metres, the highest mountain in Java, which puts up an ash plume roughly every twenty minutes. The whole assembly forms Bromo Tengger Semeru National Park, gazetted in 1982 and covering about 50,000 hectares.

What it does. Bromo is one of Indonesia's most persistently active volcanoes. Its crater is an open pit several hundred metres across that vents sulphur dioxide continuously with an audible roar, and eruptive episodes are frequent rather than exceptional — significant activity in 2010 and 2011 and again in 2015 and 2016 closed airports across East Java and Bali with ash, and evacuation zones around the cone are declared and lifted regularly by Indonesia's volcanology agency. Access to the crater rim is suspended during elevated alert levels, and checking the current status before travelling is not optional.

The people. The caldera and the slopes around it are home to the Tenggerese, a Javanese-speaking people who practise a distinct form of Hinduism and who trace their origin to the Majapahit era, having kept their religion through the Islamisation of Java. Their principal ceremony is Yadnya Kasada, held at the full moon of the fourteenth day of the Kasada month in the Tenggerese calendar. Worshippers gather at Pura Luhur Poten, the temple that stands alone on the black sand at the foot of Bromo, and then climb to the rim and throw offerings — rice, fruit, vegetables, flowers, live chickens and goats, money — into the crater. The rite derives from the legend of Roro Anteng and Joko Seger, who were granted children on the condition that the twenty-fifth be given to the mountain. Some villagers descend into the crater on ropes to catch the offerings mid-air.

What you actually see today. The standard programme is a pre-dawn one. Jeeps leave Cemoro Lawang and other rim villages between one and three in the morning and grind up to a set of viewpoints on the northern caldera wall: Penanjakan at 2,770 metres, which is the classic and the most crowded, plus King Kong Hill, Seruni Point and Bukit Cinta, which are lower and less mobbed. What you are waiting for is the moment when the light comes over the eastern rim and the sea of sand is still full of mist, with Batok's fluted cone in the foreground and Semeru smoking behind — one of the most reproduced views in Indonesia, and genuinely worth the cold. Afterwards the jeeps drop down onto the caldera floor and drive across the ash to the base of Bromo, where the last stretch is a walk over dunes and then 245 concrete steps to the rim. Horses can be hired for the flat section. On the rim there is a narrow ledge with a low railing along part of it and nothing along the rest, above a drop into the vent.

Getting there and timing. Cemoro Lawang, on the northeastern rim, is the usual base and has simple guesthouses; Malang and Probolinggo are the transport hubs, with public minibuses to the rim in the mornings only. Surabaya is three to four hours away by car. The dry season from May to October gives the clear mornings; the wet season from November to April brings cloud that regularly cancels the sunrise entirely. It is genuinely cold before dawn at this altitude — 3 to 10°C, with occasional frost on the sand in the driest months of July and August — and almost nobody arrives dressed for it. Park entry fees are higher at weekends and higher again for foreign visitors, and are paid at the gates. Jeep transport reaches the viewpoints and the caldera floor, but the ash crossing and the crater staircase are not accessible.