6,162 articles
Odintsovo
Odintsovo (Одинцово), a city in Moscow Oblast about 24 km west of Moscow; first mentioned 1627, town since 1957, about 190,000 residents; ranked first among 25 Moscow Oblast cities for quality of life in 2025.
Odorheiu Secuiesc
Odorheiu Secuiesc (Székelyudvarhely), a municipality in Harghita County, Transylvania, on the upper Târnava Mare; former center of Udvarhely Seat, known for Székelytámadt Fortress, its school-city tradition, and Roman-era fort sites.
Offenbach (city)
Offenbach am Main is an independent city in Hesse, Germany, first documented in 977. It developed from a major leather goods center to a modern design-oriented city.
Ogbia
Ogbia, a Local Government Area in Bayelsa State, Nigeria, headquarters Ogbia Town; site of Oloibiri, Nigeria's first commercial oil discovery in 1956; four clans, Ogbia Brotherhood founded 1940.
Ogbomoso
Ogbomoso (Ogbomosho), major Yoruba city in Oyo State, southwestern Nigeria, at 8.1227°N 4.2436°E; founded mid-1600s, seat of Ogbomoso North and South LGAs, home of LAUTECH and the Nigerian Baptist Convention headquarters.
Ogden, Utah
Ogden, Utah: county seat of Weber County, Utah's seventh-largest city, founded as Fort Buenaventura in 1845 and incorporated 1851; a railroad junction city and 2025 Milken second-ranked best-performing large city.
Oguta
Oguta is a lake town in Imo State, southeastern Nigeria, on Oguta Lake, the region's largest natural lake and a historic inland port for the slave and palm oil trades.
Ohrid
Ohrid (Охрид) is a lakeside city in southwestern North Macedonia, ancient Lychnidos, core of the transboundary Lake Ohrid UNESCO World Heritage property, with the oldest Slav monastery, 800+ Byzantine icons, and over 200 endemic lake species.
Oisseau-Le-Petit
Oisseau-Le-Petit, a Sarthe commune in France, preserves a restored Gallo-Roman fanum at Les Busses, a small Roman agglomeration with baths, theatre, and villa, and an 1865 hoard of 110 Iron Age gold coins.
Ōita
Ōita (大分市, Ōita-shi) is the capital of Ōita Prefecture, Kyushu, Japan, on Beppu Bay. Former Ōtomo clan stronghold and Japan's first Western-culture city; 468,996 residents (2026), 502.39 km², core city since 1997.
Ojai, California
Ojai, CA, is a small city of about 7,400 people in Ventura County, California, in a valley beside Los Padres National Forest, known as a tourism destination.
Okara
Okara (اوکاڑہ) is a city and district headquarters in Punjab, Pakistan, named after the Okaan tree; a British canal-colonization town, tehsil HQ 1918, district HQ since 1 July 1982, agricultural and dairy economy.
Okayama (city)
Okayama (岡山市), capital of Okayama Prefecture in western Japan; ordinance-designated city since 2009 with four wards, about 708,000 residents (2025), Okayama Castle, Korakuen Garden, and a major Shinkansen transport hub.
Okazaki
Okazaki (岡崎市) is a city in central Aichi Prefecture, Japan, about 35 km east of Nagoya, birthplace of Tokugawa Ieyasu at Okazaki Castle in 1542; population about 380,000, city status 1916, area 387.24 km2.
Okene
Okene is a city and LGA headquarters in Kogi State, Nigeria, cultural center of the Ebira people and seat of the Ohinoyi; 2006 census 325,623, known for cloth weaving and trade.
Oklahoma City
Oklahoma City, capital and largest city of Oklahoma, founded in the Land Run of April 22, 1889; became state capital by a June 11, 1910 vote, boomed on 1928 oil, and rebuilt downtown through the MAPS sales-tax program from 1993.
Okotoks
Okotoks is a town in southern Alberta, 18 km south of Calgary, named from the Blackfoot word for rock. Population 30,405 (2021 census); home of the Big Rock glacial erratic; growth once capped by Sheep River water supply.
Ōkuma, Fukushima
Ōkuma (大熊町) is a Fukushima coast town co-hosting the Fukushima Daiichi nuclear plant; fully evacuated in 2011, partially reopened from 2019, with about 1,500 residents living there by 2026.
Olathe, Kansas
Olathe (o-LAY-tha), Kansas: Shawnee word for "beautiful"; Johnson County seat founded 1857 by Dr. John Barton, a Santa Fe Trail stop raided by Quantrill in 1862, now the fourth largest Kansas city.
Old Delhi (पुरानी दिल्ली)
Old Delhi (Purani Dilli, Shahjahanabad) is the walled Mughal city founded by Shah Jahan in 1639, with the Red Fort, Jama Masjid, Chandni Chowk, and eight historic gates.
Old York
Old York: traditional name for York, Maine (earlier Agamenticus, Gorgeana), used by sea captains after 1664 to distinguish it from New York. Home of the Old York Gaol museum and the Old York Historical Society.
Oldenburg
Oldenburg (Oldb) is an independent city in Lower Saxony, Germany, on the Hunte river; first recorded as Aldenburg in 1108, a former ducal residence, now about 177,000 residents and a university city.
Oldham
Oldham: large town and metropolitan borough in Greater Manchester, England, among the Pennines. Former world-leading cotton-spinning town (335 mills by 1911); now known for regeneration, deprivation, Saddleworth moorland and Oldham Athletic.
Olinda, Pernambuco
Olinda, Pernambuco: historic Brazilian city founded 1535 by Duarte Coelho, raised to vila 1537, burned by the Dutch 1631, UNESCO World Heritage historic centre since 1982, famed for baroque churches and Carnival.
Olomouc
Olomouc, sixth-largest Czech city on the River Morava, former capital of Moravia, seat of Palacký University (1573) and the UNESCO-listed Holy Trinity Column (2000), with the country's second-largest urban conservation area.
Olongapo
Olongapo: highly urbanized city in Zambales, Philippines, beside Subic Bay; long administered by the U.S. Navy, made a city in 1966, population 264,903 (2024), economy tied to the Subic Bay Freeport.
Olsztyn, Warmia-Masuria
Olsztyn (Allenstein), capital of Poland's Warmian-Masurian Voivodeship; founded 1353, 165,393 residents (2025), lake city with tire industry, 2.7% unemployment, 6th in 2026 Polish quality-of-life ranking.
Olympia, Washington
Olympia, Washington: state capital and Thurston County seat at the southern tip of Puget Sound on Budd Inlet. Population 55,605 (2020); territorial capital since 1853; 287-foot capitol dome.
Ōmagari-shi
Ōmagari-shi (大曲市) was a city in Akita Prefecture, Japan, host of the National Fireworks Competition (Omagari Hanabi); on 22 March 2005 it was renamed Daisen City through a municipal merger of 1 city, 6 towns, and 1 village.
Omaha, Nebraska
Omaha, Nebraska: largest city in Nebraska, founded 1854 on the Missouri River, named for the Omaha Tribe; Union Pacific railroad hub, former meatpacking capital, 2020 population 486,051.