3,546 articles
Anticosti Island
Île d'Anticosti is a forested limestone island at the entrance to the Gulf of St. Lawrence in Quebec, Canada, and the largest island in Quebec.
Antigua
Antigua: largest island of Antigua and Barbuda in the eastern Caribbean, 280 sq km, volcanic-to-limestone geology, Ciboney settlement from 3100 BC, British sugar colony, Nelson's Dockyard UNESCO site, tourism economy, hurricane and sea-level-rise exposure.
Antilles
The Antilles are the Caribbean island chains forming the West Indies with the Bahamas: the Greater Antilles (Cuba, Jamaica, Hispaniola, Puerto Rico), continental fragments, and the volcanic Lesser Antilles arc.
Antillia
Antillia (Antilia), the Island of the Seven Cities, was a phantom island of the Atlantic drawn on portolan charts from 1424 to about 1587, tied to the seven bishops legend, sought by Columbus, and source of the name Antilles.
Antisana
Antisana (Antizana), a glacier-covered andesitic stratovolcano 50 km southeast of Quito, Ecuador, rising 5,753 m; last confirmed eruption 1801-02 (attribution disputed), source of most of southern Quito's drinking water.
Antuco
Antuco, active basaltic stratovolcano (2,979 m) in Chile's Biobío Region, Southern Volcanic Zone; Holocene sector collapse (6.4 km³ debris avalanche), 27 historical eruptions, last in 1869, 13th-ranked high-threat Chilean volcano.
Anvers Island (landform)
Anvers Island, largest island of the Palmer Archipelago off the Antarctic Peninsula, named for Antwerp in 1898; gazetteers classify it as an island, with adjacent undersea features Anvers-Hugo Trough, Palmer Basin, and Palmer Deep.
Aoba
Aoba, also known as Ambae, is a volcanic island in Penama Province, Vanuatu, rising to 1,496 m, with eruptions that evacuated its 11,000 residents in 2017 and 2018.
Aonach Eagach
Aonach Eagach (An t-Aonach Eagach, 'the notched ridge') is Glen Coe's narrow pinnacled north-wall ridge in the Scottish Highlands, linking the Munros Meall Dearg (953 m) and Sgorr nam Fiannaidh (967 m) via a committing Grade 2/3 scramble with no safe escape.
Aoraki / Mount Cook
Aoraki / Mount Cook, also Aorangi, is New Zealand's highest peak at 3,724 m in the Southern Alps, sacred to Ngāi Tahu, first climbed in 1894, lowered by the 1991 rockfall.
Aoshima, Ehime
Aoshima (青島) is a 0.49 km² island of Ozu City, Ehime, Japan, in the Seto Inland Sea, famous as a cat island where feral cats outnumbered residents; about 80 cats and four people remained by 2024.
Aoukâr
Aoukâr, also known as Erg Aoukar or Hodh, is an endorheic basin in southeastern Mauritania between Kiffa and Néma, once a lake region and heartland of the Ghana Empire.
Apaneca Range
Apaneca Range (Cuyanausul Range): chain of Pleistocene-Holocene stratovolcanoes in western El Salvador, highest peak Cerro el Aguila 2,028 m; no Holocene eruptions but fumaroles, the Ahuachapán geothermal field since 1975, and deadly 1990 and 2025 hydrothermal explosions.
Apennine Mountains
Apennine Mountains (Appennini): the mountain chain forming the geological spine of Italy, running over 1,000 km from the Alps to Sicily. An active orogenic belt from African-European plate convergence and Adriatic subduction, with 2-4 mm/yr extension and frequent earthquakes.
Api (landform)
Api is a 7,132 m peak in the Gurans Himal, far northwest Nepal, Darchula district, within Api Nampa Conservation Area. First climbed 10 May 1960 by a Japanese expedition; a 1954 Italian attempt cost three lives.
Appalachian Mountains
The Appalachian Mountains are an eastern North American mountain system from Newfoundland to Alabama, built by Paleozoic plate collisions ending about 270 million years ago, spanning Blue Ridge, Piedmont, Valley and Ridge, and plateau provinces.
Appennino Ligure
The Appennino Ligure, or Ligurian Apennines, is the stretch of the Northern Apennines lying in Liguria, Italy, the eastern arm of the arc enclosing the region.
Ara Sima
Ara Sima (Ara Shima, Ostrov Rogachëva, 荒島) is a small uninhabited islet 350 m off the southeast coast of Kunashir, Kuril Islands, Russia; a 56 m high grassy rock hosting a rhinoceros auklet colony of 17,000–30,000 pairs.
Arabian Desert
Arabian Desert: the arid region covering most of the Arabian Peninsula, eastern half of the Saharo-Arabian belt. Contains the Rub' al Khali (Empty Quarter), the world's largest continuous sand desert at about 660,000 square kilometers, with a history of Miocene hyperaridity and recurrent humid phases.
Arabian Interior
Arabian Interior, FEOW ecoregion 440, Palearctic xeric endorheic-basin freshwater ecoregion covering the Arabian Peninsula's internal basins into Jordan and Syria; few freshwater habitats, 10 fish species with 8 endemics, key site the Azraq Oasis.
Arabian Peninsula (شبه الجزيرة العربية)
The Arabian Peninsula (شبه الجزيرة العربية, Jazīrat al-ʿArab) is southwestern Asia's arid peninsula with Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, the UAE, and Yemen; defined by Red Sea rifting, oil-bearing sedimentary basins, extreme water scarcity, and accelerating warming.
Aracar
Aracar is a 6,095 m Holocene stratovolcano in Salta Province, northwestern Argentina, near the Chilean border, with a 1-1.5 km summit crater lake, no confirmed historical eruptions, and no monitoring.
Aragats
Aragats (Արագած) is Armenia's highest peak, a 4,090-4,095 m andesitic-dacitic stratovolcano 40 km NW of Yerevan, center of the Aragats Volcanic Province with Quaternary ignimbrites, Pleistocene eruptions to ~0.49 Ma, paleoglaciers, and a cosmic ray station.
Arakan Mountains
The Arakan Mountains, also called the Rakhine Mountains or Arakan Yoma, are a mountain range in western Myanmar that separates the Bay of Bengal coast from the Irrawaddy basin.
Araku Valley
Araku Valley, a tribal upland in the Eastern Ghats of Alluri Sitharama Raju district, Andhra Pradesh, near Odisha, is a hill-station tourist destination and the origin of GI-registered Araku Valley Arabica Coffee, grown organically by Adivasi smallholders via the SAMTFMACS cooperative.
Aran Islands
The Aran Islands (Oileáin Árann) are three limestone Gaeltacht islands at the mouth of Galway Bay, Ireland: Inis Mór, Inis Meáin, Inis Oírr. Population 1,347 (2022), famous for Dún Aonghasa, St Enda's monastery, and the Aran sweater.
Aravalli Range
Aravalli Range, ancient eroded fold-mountain system in Gujarat, Rajasthan, Haryana, and Delhi; India's oldest range (Precambrian, over 2 billion years); Guru Shikhar 1,722 m; green barrier against the Thar Desert; 2025 Supreme Court mining definition.
Arc Dome
Arc Dome, also called Toiyabe Dome, is the highest summit of the Toiyabe Range in Nye County, Nevada, rising to 11,774 feet with a 5,214-foot prominence.
Archipel d'Hochelaga
Archipel d'Hochelaga (Hochelaga Archipelago) is the group of over 320 islands at the confluence of the St. Lawrence and Ottawa rivers in Quebec, including Montreal Island, Laval, and Perrot; name coined by Marie-Victorin in 1935, officialized in 1985.
Archipelago
Archipelago: a group or chain of islands in an ocean, lake, or river; from Italian arcipelago, originally the Aegean Sea. Forms volcanically, glacially, or tectonically; UNCLOS defines archipelagic States with baselines at 1:1 to 9:1 water-to-land.