Landforms and terrestrial features

Buka Island

Buka Island, northern counterpart of Bougainville Island in Papua New Guinea's Autonomous Region of Bougainville; raised coral limestone island hosting Buka Town, the region's capital, separated from Bougainville by the fast-flowing Buka Passage.

Bukit Raya

Bukit Raya (Gunung Bukit Raya), Central Kalimantan, is the highest peak of Indonesian Borneo at about 2,278 m, in Bukit Baka Bukit Raya National Park; distinct from Malaysian and Pekanbaru namesakes.

Buku Sibela

Buku Sibela (Gunung Sibela) is the highest peak of Bacan Island and of North Maluku province, Indonesia, about 2,085-2,111 m with equal prominence, in Gunung Sibela Nature Reserve, a young exhumed metamorphic block complex.

Bull Canyon Formation

Bull Canyon Formation: Upper Triassic (Norian) mudstone formation in east-central New Mexico, Chinle/Dockum Group; named by Lucas and Hunt (1989); type fauna of the Revueltian land-vertebrate faunachron.

Bulu Kandela

Bulu Kandela (Buyu Kondorung) is a 2,870 m ultra-prominent mountain in Central Sulawesi, Indonesia, with 2,250 m prominence; first recorded ascent 27 October 2013 by Tadulako University students; distinct from the 855 m Buyu Kandela peak and from Katopasa.

Bulu Rantemario

Bulu Rantemario (Puncak Rantemario), summit of Gunung Latimojong in South Sulawesi, is Sulawesi's highest peak at 3,478 m (GPS about 3,440 m), a non-volcanic Seven Summits Indonesia highpoint climbed via the Karangan route.

Bundelkhand

Bundelkhand is a semi-arid region of central India, about 70,000 km² across southern Uttar Pradesh and northern Madhya Pradesh, named for the Bundela dynasty, known for the Chandelas, Khajuraho, recurrent drought, and the Ken-Betwa Link Project.

Bureinsky Ridge

Bureinsky Ridge (Буреинский хребет), a mountain ridge in Khabarovsk Krai and Amur Oblast, Russian Far East, part of the Bureinsky Highlands west of the Amur, with Late Pleistocene glacial landforms and the Bureinskiy Nature Reserve.

Buru

Buru (Boeroe) is an island in eastern Indonesia known for its mountainous interior, colonial history, and its notoriety as a political prison between 1969 and 1979.

Busuanga Island

Busuanga Island: largest island of the Calamian Group, northern Palawan, Philippines (~971 km²), split into Busuanga and Coron municipalities; non-volcanic continental-fragment geology, dry Dec–May climate, 1944 Coron Bay shipwrecks, and a dugong stronghold.

Butler Cave Conservation Society

Butler Cave Conservation Society (BCCS), founded November 1968 and incorporated in Virginia in 1970, is a non-profit cave conservancy in Burnsville Cove, Bath and Highland Counties, Virginia, owning and managing Butler Cave, over 18 miles long and the fifth longest in Virginia.

Butler Island

Butler Island, an ice rise in the Larsen Ice Shelf on the Black Coast, Antarctic Peninsula, at 72°12'S 60°20'W; named in 1953 for FIDS commander Kenelm Pierce-Butler and host to a BAS automatic weather station.

Buttress Hill

Buttress Hill, a flat-topped Antarctic hill about 2,300 ft high with west-facing rock cliffs, overlooks Duse Bay in the northeast Antarctic Peninsula at 63°34'S, 57°03'W; named descriptively by the FIDS after their 1946 survey.

Bylot Island

Bylot Island, Nunavut, an 11,100 km² uninhabited Canadian Arctic island off northern Baffin Island in Sirmilik National Park; a biodiversity hotspot with a greater snow goose colony and a 35-year tundra food web monitoring program.

Cadeuil amber Formation

Cadeuil amber deposit, Charente-Maritime, France; Cretaceous (uppermost Albian-lowermost Cenomanian) fossil resin found in a 2001 sand quarry, yielding mites, insects of at least 20 families in 9 orders, algae, and mycelia.

Caelius Mons

Caelius Mons, the Caelian Hill (Celio), the most south-easterly of Rome's Seven Hills; originally Querquetulanus, renamed for the Etruscan Caeles Vibenna; fire of A.D. 27, temple of Divus Claudius, Macellum Magnum.

Caichinque

Caichinque is a Pleistocene-Holocene stratovolcano complex (Volcano Number 355104) in Chile's Central Volcanic Zone, rising 4,458 m between Salar Capur and Salar Talar, with more than six andesitic-to-dacitic vents, no recorded Holocene eruptions, and uncertain age.

Cairn

Cairn: a human-made pile of stones (Irish carn), used from the Neolithic onward as burial monuments, chambered tombs such as Clava, landmarks, and modern hiking trail markers, distinct from earth-built tumuli.

Cairn Gorm

Cairn Gorm (Càrn Gorm, blue mountain) is a 1,245 m Scottish Highland mountain, Britain's sixth highest, in the Cairngorms National Park; home to a ski area, the £19.5m funicular railway (reopened 2025), and namesake of cairngorm quartz.

Calabozos

Calabozos is a 26 x 14 km late-Pleistocene caldera in the central Chilean Andes at 35.5°S, source of the Loma Seca Tuff ash flows (0.8, 0.3, 0.15 Ma, over 1,000 km3 total), with Holocene Descabezado Chico vents and a long-lived geothermal system.

Calamian Islands

Calamian Islands (Calamianes), northernmost island group of Palawan Province, Philippines: Busuanga, Coron, Culion, Linapacan. Reefs hold 70% of Philippine coral and seagrass species; over ten MPAs; Tagbanwa ancestral waters; Coron tourism boom.

Calanshio Sand Sea

Calanshio Sand Sea (سرير كلانشيو الرمال الكبير), also Calanscio Sand Sea, is a ~62,000 km² erg in eastern Libya running 500 km from Jaghbub and Jalo to Kufra, continuous with Egypt's Great Sand Sea, with north–south seif dunes over 110 m high.

Calcaire de Caen Formation

Calcaire de Caen Formation (pierre de Caen, Caen stone): Early-Middle Bathonian fine bioclastic limestone, 20-25 m thick, under the plain of Caen, Normandy; source of the building stone used since the 11th century in Caen's abbeys and English cathedrals.