Parks, protected areas, and geographic heritage sites

Oki Islands UNESCO Global Geopark

Oki Islands UNESCO Global Geopark (隠岐ユネスコ世界ジオパーク) covers four inhabited islands in the Sea of Japan off Shimane, Japan; designated 2013, UNESCO 2015, third revalidation 2025, area 673.5 km².

Okinawa Children's Zoo & Museum

Okinawa Children's Zoo & Museum (沖縄こどもの国) is a zoo and children's museum in Okinawa City, Japan, opened in 1970; it holds about 1,000 animals and Okinawa's only children's museum.

Okinawa Churaumi Aquarium

Okinawa Churaumi Aquarium (沖縄美ら海水族館), in Motobu, Okinawa, Japan, opened November 2002; its 7,500 m³ Kuroshio Sea tank holds whale sharks and manta rays, with world-first captive breeding records.

Okinawa Slow Wind Forest (風楽風遊の森) is a themed forest attraction at 2146 Chibana, Okinawa City, Japan, part of the Southeast Botanical Gardens resort; its name ties to the local 'Slow' regional currency used for admission discounts.

Okinohata Aquarium

Okinohata Aquarium (おきのはた水族館) was a small private aquarium in Yanagawa, Fukuoka, opened April 2010 by fish-market chief Kondo Junzo to display Ariake Sea species; since 2016 it continues as the Yanagawa Ariake Sea Aquarium run by NPO SPERA with student directors.

Oklahoma City National Memorial

Oklahoma City National Memorial, a National Park Service-affiliated memorial and museum at the Murrah Federal Building bombing site, honoring the 168 killed on April 19, 1995, with the Field of Empty Chairs, Gates of Time, and Survivor Tree.

Okolitsa Rural Park

Okolitsa (Сельский парк «Околица») is a rural park and open-air wooden-architecture museum in Zorkaltsevo, 17 km from Tomsk, Russia; first rural park beyond the Urals and venue of the Axe Festival since 2013.

Oktyabrsky Zoo

Акцябрскі заапарк (Oktyabrsky Zoo), a small state zoo in Akciabrski, Gomel Oblast, Belarus, opened May 6, 2003; about 1.8 ha, over 60 species including Red Book animals, one of five Belarusian zoos.

Okwangwo Biosphere Reserve

The Okwangwo Biosphere Reserve is a UNESCO biosphere reserve designated in 2020 in Cross River State, Nigeria, occupying the northern part of Cross River National Park between the Cross and Sanga rivers.

Old and New Towns of Edinburgh

Old and New Towns of Edinburgh: UNESCO World Heritage Site (1995, criteria ii and iv, 443 ha) pairing Edinburgh's organic medieval Old Town with the planned neoclassical Georgian New Town built 1767-1890 from James Craig's 1767 plan.

Old Bouleuterion/Metroon

Old Bouleuterion/Metroon: late 6th-century BC council house on the west side of the Athenian Agora housing the Boule of 500, later the state archive and sanctuary of the Mother of the Gods, replaced c. 150 BC by the Hellenistic Metroon.

Old Bridge Area of the Old City of Mostar

Old Bridge Area of the Old City of Mostar (Stari Most), UNESCO World Heritage Site inscribed 2005; 16th-century Ottoman arch bridge by Mimar Hajruddin, destroyed 9 November 1993, rebuilt 2004 as a symbol of reconciliation.

Old Burrow (United Kingdom)

Old Burrow (Old Barrow) is a mid-first-century AD Roman fortlet on the north Devon coast at Countisbury, Exmoor, a scheduled monument with square double-ditched inner enclosure inside a 98 m circular outer enclosure, occupied briefly around AD 48-54 to watch the Silures.

Old City of Acre

The Old City of Acre, also known as Akko (عكّا), is a walled port-city in northern Israel, a UNESCO World Heritage Site inscribed in 2001.

Old City of Berne

Old City of Berne (Altstadt von Bern), medieval town core of Bern, Switzerland, UNESCO World Heritage site since 1983 (criterion iii, 91.86 ha). Founded 1191 by Berchtold V of Zähringen; known for six kilometres of arcades, sandstone buildings after the 1405 fire, and 16th-century fountains.

Old City of Dubrovnik

Old City of Dubrovnik (Stari grad Dubrovnik): walled medieval core of Dubrovnik, Croatia, UNESCO-listed since 1979; 1,940 m stone walls, Minčeta, Revelin, Bokar and St John fortresses; damaged in 1667 earthquake and the 1991–1995 war.

Old City of Salamanca

Old City of Salamanca (Ciudad Vieja de Salamanca), UNESCO World Heritage Site since 1988 in Castilla y León, Spain: historic university city founded around a 1218 university, with the Baroque Plaza Mayor, two cathedrals, and golden Villamayor sandstone architecture.

Old City of Sana'a

Old City of Sana'a (صنعاء القديمة), Yemen's historic walled capital core at 2,200 m, inhabited over 2,500 years; UNESCO World Heritage Site since 1986, on the Danger List since 2015, with rammed-earth tower-houses and the Great Mosque of 627 AD.

Old City of Zamość

Old City of Zamość (Stare Miasto w Zamościu), Renaissance planned town in southeastern Poland founded 1580 by Jan Zamoyski, designed by Bernardo Morando as an Italian-style ideal city; UNESCO World Heritage Site since 1992, Monument of History since 1994.

Old Durham

Old Durham: presumed Roman villa and bath-house site east of Durham City, England, 2nd-4th centuries AD, found in 1939 during sand quarrying; the northernmost high-status rural estate centre known in the Roman empire.

Old Faithful Historic District

Old Faithful Historic District, Yellowstone National Park: NRHP-listed 1982 concession complex around Old Faithful Inn (1904, Robert Reamer), Old Faithful Lodge, stores, and cabins in the Upper Geyser Basin.

Old Faithful Inn

Old Faithful Inn is a 1904 log hotel in Yellowstone National Park, designed by Robert Reamer, the world's largest log structure and the model for National Park Rustic architecture, a National Historic Landmark since 1987.

Old Havana

Old Havana (La Habana Vieja) is Havana's 1519-founded colonial historic district, a UNESCO World Heritage Site since 1982 with five plazas and Spanish fortifications, restored by the Office of the Historian through self-financing tourism revenue.

Old Jewish cemetery, Hebron

The Old Jewish Cemetery of Hebron (בית העלמין העתיק) is a historic Jewish burial ground on a hill west of Tel Hebron near the Cave of the Patriarchs, with about 5,000 graves in Karaite, Sephardic, rabbinic, and Ashkenazic sections, destroyed under Jordanian rule and restored from 1975.

Old Jewish Cemetery, Prague

The Old Jewish Cemetery in Prague's Josefov district served the city's Jewish community from the 15th century until 1787, its about 12,000 tombstones marking burials stacked up to twelve deep.

Old Kilpatrick

Old Kilpatrick, West Dunbartonshire, Scotland, is the site of the western terminal fort of the Antonine Wall. Excavated 1913-1931, it yielded distance slabs, a Jupiter altar, and the Wall's latest dated coin (Lucilla, 164-169).

Old Man of the Lake

Old Man of the Lake: 30-foot hemlock log floating upright in Oregon's Crater Lake since 1896; carbon dated beyond 450 years; traveled 62.1 miles in 1938; tied up at Wizard Island in 1988 before storms hit.

Old Manor House

Old Manor House, Walton-on-Thames: Grade I listed 14th-century timber-framed hall-and-cross-wings house on Manor Road, Surrey, also called Bradshaw's House after John Bradshaw, reputed signer of Charles I's death warrant.

Old Montreal

Old Montreal (Vieux-Montréal) is Montreal's historic district, founded 1642, declared a Quebec historic district in 1964. Covers Notre-Dame Basilica, Place Jacques-Cartier, rue Saint-Paul, and current pedestrianization and PHI Contemporary projects.