Gunung Bromo volcanic crater. Volcanic vapours rising from Broom's crater on the volcanic peak of Gunung (Mount) Bromo. The cracked ground, made up of solidified lava, demonstrates the pressure that occurs during an eruption of volcanic gases. Gunung Bromo is a young volcano that has formed in the ancient 10-kilometre-wide Tengger Caldera. Photographed in 1999 in the Bromo-Tengger-Semeru National Park, Java, Indonesia.