Mount Bromo (Indonesian: Gunung Bromo), is an active volcano and part of the Tengger massif, in East Java, Indonesia. At 2,329 meters 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.

Mount Bromo sits in the middle of a vast plain called the Sand Sea (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 (2,270 meters) (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, also Mount Semeru or Gunung Semeru - located in East Java is the highest mountain on the island of Java, Indonesia. The stratovolcano is also known as Mahameru, meaning 'The Great Mountain'.

Java (Indonesian: Jawa) is an island of Indonesia and the site of its capital city, Jakarta. Once the center of powerful Hindu-Buddhist kingdoms, Islamic sultanates, and the core of the colonial Dutch East Indies, Java now plays a dominant role in the economic and political life of Indonesia. Home to a population of 130 million in 2006, it is the most populous island in the world, ahead of Honshū, the main island of Japan. Java is also one of the most densely populated regions on Earth.

Formed mostly as the result of volcanic events, 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 is the native language of 60 million people in Indonesia, most of whom live on Java. Most residents are bilingual, with Indonesian as their second language. While the majority of Javanese are Muslim, Java has a diverse mixture of religious beliefs and cultures.

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, ash and gases to escape from below the surface. The word volcano is derived from the name of Vulcano island off Sicily which in turn, was named after Vulcan, the Roman god of fire.

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 (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

Oceania (sometimes Oceanica) is a geographical, and often geopolitical, region consisting of numerous lands—mostly islands in the Pacific Ocean and vicinity. The term "Oceania" was coined in 1831 by French explorer Dumont d'Urville. The term is also sometimes used to denote a continent comprising Australia and proximate Pacific islands, and is one of eight terrestrial ecozones.

The boundaries of Oceania are defined in a number of ways. Most definitions include parts of Australasia such as Australia, New Zealand, and New Guinea, and all or part of the Malay Archipelago. Ethnologically, the islands that are included in Oceania are divided into the subregions of Melanesia, Micronesia, and Polynesia.

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 also includes neighboring Madura and islands to the east of it, as well as the Bawean islands. The administrative center of the province is located in Surabaya, the second largest city in Indonesia and a major industrial center and port.