Bolivia–Chile border in the context of Cordillera Occidental (Central Andes)

Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco, warm valleys, high-altitude Andean plateaus, and snow-capped peaks, encompassing a wide range of climates and biomes across its regions and cities. It includes part of the Pantanal, the largest tropical wetland in the world, along its eastern border. It is bordered by Brazil to the north and east, Paraguay to the southeast, Argentina to the south, Chile to the southwest, and Peru to the west. The seat of government is La Paz, which contains the executive, legislative, and electoral branches of government, while the constitutional capital is Sucre, the seat of the judiciary. The largest city and principal industrial center is Santa Cruz de la Sierra, located on the Llanos Orientales (eastern tropical lowlands), a mostly flat region in the east of the country with a diverse non-Andean culture.

The sovereign state of Bolivia is a constitutionally unitary state divided into nine departments. Its geography varies as the elevation fluctuates, from the western snow-capped peaks of the Andes to the eastern lowlands, situated within the Amazon basin. One-third of the country is within the Andean mountain range. With an area of 1,098,581 km (424,164 sq mi), Bolivia is the fifth-largest country in South America after Brazil, Argentina, Peru and Colombia, and, alongside Paraguay, is one of two landlocked countries in the Americas. It is the largest landlocked country in the Southern Hemisphere. Bolivia had a population of 11.4 million as of the latest census in 2024. It is multiethnic, including Amerindians, Mestizos, and the descendants of Europeans and Africans. Spanish is the official and predominant language, although 36 indigenous languages also have official status, of which the most commonly spoken are Guaraní, Aymara, and Quechua.

Ollagüe (Spanish pronunciation: [oˈʎaɣwe]) or Ullawi (Aymara: [uˈʎawi]) is a massive andesite stratovolcano in the Andes on the Bolivia–Chile border, within the Antofagasta Region of Chile and the Potosi Department of Bolivia. Part of the Central Volcanic Zone of the Andes, its highest summit is 5,868 metres (19,252 ft) above sea level and features a summit crater that opens to the south. The western rim of the summit crater is formed by a compound of lava domes, the youngest of which features a vigorous fumarole that is visible from afar.

Ollagüe is mostly of Pleistocene age. It started developing more than one million years ago, forming the so-called Vinta Loma and Santa Rosa series mostly of andesitic lava flows. A fault bisects the edifice and two large landslides occurred in relation to it. Later two groups of dacitic lava domes formed, Ch'aska Urqu on the southeastern slope and La Celosa on the northwestern. Another centre named La Poruñita formed at that time on the western foot of the volcano, but it is not clear whether it is part of the main Ollagüe system. Activity at the summit continued during this time, forming the El Azufre sequence.

Dispute over the Status and Use of the Waters of the Silala (Chile v. Bolivia) was a case at the International Court of Justice. In the case, Chile petitioned the Court to declare the Silala River an "international watercourse whose use by Chile and Bolivia is governed by customary international law." Chile presented the case in 2016 while the Bolivian case against Chile, Obligation to Negotiate Access to the Pacific Ocean, was still ongoing. According to France 24 the case came as a surprise. The upper area of Silala River around the Bolivia–Chile border have had its flow enhanced by channels since 1928 for sanitary reasons given that the river sources lie in small wetlands. These wetlands are bofedales with insect fauna and were intervened for better drainage after fly eggs were detected in the water supply of the city of Antofagasta.

Bolivia's position is that the waters of the Silala flow into Chile through artificial channels, while Chile claims that it is an international river. Bolivia also sought a ruling that specified that any future enhanced flow into Chile had to be the subject of an agreement.

Licancabur (Spanish pronunciation: [likaŋkaˈβuɾ]) is a prominent, 5,916-metre-high (19,409 ft) stratovolcano on the Bolivia–Chile border in the Central Volcanic Zone of the Andes. It is capped by a 400–500-metre-wide (1,300–1,600 ft) summit crater which contains Licancabur Lake, a crater lake that is among the highest lakes in the world. There are no glaciers owing to the arid climate. Numerous plants and animal species live on the mountain. The volcanoes Sairecabur and Juriques are north and east of Licancabur, respectively.

Licancabur formed on top of ignimbrites produced by other volcanoes, and has been active during the Holocene. Three stages of lava flows emanated from the edifice and have a young appearance. Although no historical eruptions of the volcano are known, lava flows extending into Laguna Verde have been dated to 13,240±100 years before present, and there may be residual heat in the mountain. The volcano has primarily erupted andesite, with small amounts of dacite and basaltic andesite.