Mount Bromo, Java

Mount Bromo (Indonesian: Gunung Bromo), is an active volcano and part of the Tengger massif, in East Java, Indonesia. At 2,329 metres (7,641 ft) it is not the highest peak of the massif, but is the most well known. The massif area is one of the most visited tourist attractions in East Java, Indonesia. The volcano belongs to the Bromo Tengger Semeru National Park. The name of Bromo derived from Javanese pronunciation of Brahma, the Hindu creator god.

Mount Bromo sits in the middle of a vast 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 best views from Mount Bromo to the Sand Sea below and the surrounding volcanoes are at sunrise. The viewpoint on Mount Penanjakan can also be reached on foot in about two hours. From inside the caldera, sulfur is collected by workers.

Semeru, or Mount Semeru (Indonesian: Gunung Semeru), is a volcano located in East Java, Indonesia. It is the highest mountain on the island of Java. The stratovolcano is also known as Mahameru, meaning 'The Great Mountain. The name derived from Hindu-Buddhist mythical mountain of Meru or Sumeru, the abode of gods.

Java (Indonesian: Jawa) is an island of Indonesia. With a population of 135 million (excluding the 3.6 million on the island of Madura which is administered as part of the provinces of Java), Java is the world's most populous island, and one of the most densely-populated places on the globe. Java is the home of 60 percent of the Indonesian population. The Indonesian capital city, Jakarta, is located on western Java. Much of Indonesian history took place on Java. It was the center of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the Indonesian struggle for independence during the 1930s and 40s. Java was also occupied by the Imperial Japanese Army from 1942 through the defeat of the Japanese Empire in 1945, and this put a temporary end to all thoughts of independence. Java dominates the Indonesian social, political, and economic life.

Formed mostly as the result of volcanic eruptions, Java is the 13th largest island in the world and the fifth largest island in Indonesia. A chain of volcanic mountains forms an east-west spine along the island. It has three main languages, though Javanese is dominant, and it is the native language of about 60 million people in Indonesia, most of whom live on Java. Most ot its residents are bilingual, with Indonesian as their first or second languages. While the majority of the people of Java are Moslem, Java has a diverse mixture of religious beliefs, ethnicities, and cultures.

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface.

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust in the interiors of plates, e.g., in the East African Rift, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "Plate hypothesis" volcanism. Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core-mantle boundary, 3,000 km deep in the Earth.

Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific (ethnologically divided into the subregions of Melanesia, Micronesia, and Polynesia) to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago. The term is sometimes used more specifically to denote a continent comprising Australia and proximate islands, or biogeographically as a synonym for either the Australasian ecozone (Wallacea and Australasia) or the Pacific ecozone (Melanesia, Polynesia, and Micronesia apart either from New Zealand or from mainland New Guinea).

Bromo Tengger Semeru National Park is located in East Java, Indonesia, to the east of Malang and to the southeast of Surabaya, the capital of East Java. It is the only conservation area in Indonesia that has a sand sea, the Tengger Sand Sea (Indonesian: Laut Pasir Tengger), across which is the caldera of an ancient volcano (Tengger) from which four new volcanic cones have emerged. This unique feature covers a total area of 5,250 hectares at an altitude of about 2,100 m. The massif also contains the highest mountain in Java, Mount Semeru (3,676 m), four lakes and 50 rivers.

The Tengger Sand Sea has been protected since 1919. The Bromo Tengger Semeru National Park was declared a national park in 1982.

East Java (Indonesian: Jawa Timur, Javanese: Jawa Wétan) is a province of Indonesia. It is located on the eastern part of the island of Java and includes neighboring Madura and islands to its east (the Kangean and Sapudi groups) and to its north (Bawean and the Masalembu Islands. The provincial capital is Surabaya, the second largest city in Indonesia and a major industrial center and port.