Rising from the guts of the ancient Tengger caldera, Gunung Bromo (2329m) is one of three volcanoes to have emerged from a vast crater, stretching 10km across. Flanked by the peaks of Kursi (2581m) and Batok (2440m), the smouldering cone of Bromo stands in a sea of ashen, volcanic sand, surrounded by the towering cliffs of the crater’s edge. Just to the south, Gunung Semeru (3676m), Java’s highest peak and one of its most active volcanoes, throws its shadow – and occasionally its ash – over the whole scene.