Mount Bromo

Mount Bromo sits in the middle of a plain called the "Sea of Sand" (Javanese: Segara Wedi or Indonesian: Lautan Pasir), a protected nature reserve since 1919. The typical way to visit Mount Bromo is from the nearby mountain village of Cemoro Lawang. From there it is possible to walk to the volcano in about 45 minutes, but it is also possible to take an organised jeep tour, which includes a stop at the viewpoint on Mount Penanjakan (2,770 m or 9,088 ft) (Indonesian: Gunung Penanjakan). The viewpoint on Mount Penanjakan can also be reached on foot in about two hours.

Mount Ijen

The Ijen volcano complex is a group of composite volcanoes located on the border between Banyuwangi Regency and Bondowoso Regency of East Java, Indonesia. It is inside a larger caldera Ijen, which is about 20 kilometers wide.

There are several tourist destinations on Mount Ijen complex, including:

- Blue fire crater

Since National Geographic mentioned the electric-blue flame of Ijen, tourist numbers increased. The phenomenon has occurred for a long time, but beforehand there was no midnight hiking. A two-hour hike is required to reach the rim of the crater, followed by a 45-minute hike down to the bank of the crater. The blue fire is ignited sulfuric gas, which emerges from cracks at temperatures up to 600 °C (1,112 °F). The flames can be up to five meters (16 feet) high; some of the gas condenses to liquid and is still ignited. It is the largest blue flame area in the world and local people refer to it as 'Blue Fire'.

- Sulfur mining at Ijen

An active vent at the edge of the lake is a source of elemental sulfur, and supports a mining operation. Escaping volcanic gases are channeled through a network of ceramic pipes, resulting in condensation of molten sulfur.