3,546 articles
Isle of Arran
Isle of Arran, "Scotland in miniature": largest island in the Firth of Clyde, Scotland's seventh largest, 167 sq mi, Goat Fell 874 m, population 4,629 (2011); UNESCO Global Geopark since April 2025, Neolithic monuments at Machrie Moor, CalMac ferries from Ardrossan and Troon.
Isle of Bute
Isle of Bute (Eilean Bhòid), a Firth of Clyde island in Argyll and Bute, Scotland; population 6,039 (2022), main town Rothesay, ferries from Wemyss Bay and Colintraive, Rothesay Castle and Mount Stuart House.
Isle of Lewis
Isle of Lewis: northern two-thirds of the largest Outer Hebrides island, Scotland, main town Stornoway. Known for Lewisian gneiss (~2900 Ma), Norse place-names, the Lewis Chess-pieces hoard, and crofting, fishing and weaving economy.
Isle of Mull
The Isle of Mull (An t-Eilean Muileach) is the second largest Inner Hebrides island, Scotland, population about 3,000, reached by a 45-minute CalMac ferry from Oban to Craignure, with Tobermory as its main town.
Isle of Portland
The Isle of Portland is a tied limestone island off Dorset, England, joined to the mainland by Chesil Beach tombolo beside the Fleet lagoon. Known for Portland Stone quarried since the 14th century, Jurassic Coast World Heritage status, and landslipping coasts.
Isle of Sheppey
Isle of Sheppey (Sceapige, Sheep Island): Kent island in the Thames estuary separated by the Swale, with Sheerness, Minster, Queenborough, Leysdown; eroding London Clay cliffs, 1909 Short brothers aviation, Sheppey Crossing (2006).
Isle of Skye
Isle of Skye (An t-Eilean Sgitheanach), largest Inner Hebrides island, 1,656 km2, ~13,000 residents, over 650,000 visitors a year; linked by the 1996 Skye Bridge, known for the Cuillin and overtourism pressures.
Isle of Wight
Isle of Wight: island and unitary authority off southern England, separated from the mainland by the Solent; 146.8 sq miles, about 140,000 people; designated a UNESCO Biosphere Reserve on 19 June 2019, the seventh in the UK.
Isle Royale
Isle Royale is a roadless archipelago in northwestern Lake Superior that forms Isle Royale National Park in Keweenaw County, Michigan, home to a wolf-moose study running since 1958.
Isles of Scilly
The Isles of Scilly are a granite archipelago of over 150 islands about 28 miles southwest of Land's End, Cornwall, with five inhabited islands, dense prehistoric archaeology, a 1975 AONB, and a sui generis island council.
Islet
Islet: a very small island, bigger than a rock and smaller than an island, formed by volcanic, fluvial, or reef-sediment processes; also the islets of Langerhans, the insulin-secreting pancreatic cell clusters central to diabetes.
Islita Casilda
Islita Casilda is a small island in Chile's Región de Magallanes y de la Antártica Chilena at 53°02'S, 73°57'W, elevation 52 m; GeoNames ID 3896290, Wikidata Q23650898, near Punta Kings and Península Blanca.
Isluga
Isluga (Volcán Isluga) is a 5,550 m stratovolcano in Chile's Tarapacá Region near the Bolivian border; last erupted 1913, 1878 lava flow destroyed towns; within Volcán Isluga National Park.
Ismoil Somoni Peak
Ismoil Somoni Peak, formerly Stalin Peak and Communism Peak (Пик Коммунизма), is Tajikistan's highest mountain at 7,495 m in the Pamirs' Academy of Sciences Range, first climbed in 1933 by Yevgeniy Abalakov and a Snow Leopard challenge peak.
Isthmus
Isthmus: a narrow strip of land connecting two larger landmasses and separating two bodies of water, exemplified by the Isthmuses of Panama and Suez, canal sites, and the ~2.8 Ma Panama land bridge.
Isthmus of Fitzcarrald
Isthmus of Fitzcarrald (Istmo de Fitzcarrald) is a low land portage in the Peruvian Amazon connecting the Ucayali and Madre de Dios basins, named for Carlos Fitzcarrald's 1896 portage.
Isthmus of Panama
Isthmus of Panama: land bridge joining North and South America and separating Atlantic from Pacific. Formed by volcanic arc collision; closure date debated (2.8 Ma vs 13–15 Ma); drove the Great American Biotic Interchange.
Isthmus of Tehuantepec
Isthmus of Tehuantepec, Mexico's narrowest land bridge between the Gulf of Mexico and Pacific, roughly 200 km across Oaxaca and Veracruz; site of Chivela Pass, Tehuano winds, the 1894 Tehuantepec Railway, and the modern CIIT interoceanic corridor.
Isthmus Peak
Isthmus Peak (Alaska) is an unofficially named 6,532 ft (1,991 m) summit in the Kenai Mountains on the Kenai Peninsula, with 5,810 ft prominence (an Alaska ultra), first climbed March 30, 1967, in Chugach National Forest; distinct from New Zealand's Isthmus Peak near Wānaka.
Istria
Istria (Istra) is the largest Adriatic peninsula, 3,476 km², shared by Croatia (90%), Slovenia, and Italy; historically Roman, Venetian, Habsburg, and Italian territory, now mostly Croatia's Istrian County.
Italian Peninsula & Islands
Italian Peninsula & Islands, FEOW freshwater ecoregion 416, Palearctic temperate coastal rivers covering central-southern Italy plus Corsica, Sardinia, Sicily, and Malta; Tiber is its largest river.
Itat Formation
Itat Formation, Middle Jurassic (Bathonian, 168.3-166.1 Ma) formation in Krasnoyarsk Territory, West Siberia, Russia. Its Berezovsk coal mine site yielded Russia's first Middle Jurassic mammals, the tyrannosauroid Kileskus, and Asia's most diverse Middle Jurassic vertebrate assemblage.
Iturup
Iturup (Etorofu, 択捉島), the largest Kuril island, is a volcanic island controlled by Russia and claimed by Japan as one of the four Northern Territories, seized by the USSR in 1945; Putin made his first visit there in August 2026.
Iwatesan
Iwatesan (岩手山), Mount Iwate, an active 2,038 m stratovolcano in Iwate Prefecture, Honshu, Japan, called Nanbu Fuji; twin Nishi-Iwate and Higashi-Iwate cones, seven sector collapses, historic eruptions in 1686, 1732, and 1919, and 1998 unrest.
Iwembere Steppe
Iwembere Steppe (Wembere Steppe, Wembere Plain) is a seasonally flooded grassland wetland in central Tanzania at about 1,000 m, drained by the Wembere River into Lake Eyasi, an unprotected Important Bird Area famous for waterbird heronries and the Vulnerable Karamoja Apalis.
Iwo Jima (硫黄島)
Iwo Jima (硫黄島, Iōtō, "sulfur island") is a small volcanic island in Japan's Volcano Islands, the site of the fierce Battle of Iwo Jima in 1945.
Izalco
Izalco (Volcán de Izalco) is a 1,950 m stratovolcano on Santa Ana's southern flank, El Salvador, born in 1770; its nightly glow earned the name Lighthouse of the Pacific until eruptions ended in 1966.
Izu Islands
Izu Islands (伊豆諸島): nine volcanic islands south of Tokyo Bay, part of Tokyo Metropolis along with the Ogasawara Islands. About 21,500 residents; active volcanoes on the Izu-Bonin arc, including Izu-Oshima and Miyakejima.
Jabal Abyad Plateau
Jabal Abyad Plateau (Jebel Abyad, Gebel Abyad) is a plateau in Northern State, Sudan, at 19°N 29°E, known for the Gebel Abyad Formation, the southernmost marine Early Tertiary limestone outcrops in northeast Africa; distinct from the Saudi volcano of the same name.
Jabal al-Druze (جبل الدروز)
Jabal al-Druze (جبل الدروز), also Jabal al-Arab, is a 1,803 m basaltic volcanic massif in Syria's As-Suwayda governorate, heartland of the Druze community, named after Druze settlement from the 16th to 19th centuries.