Waters and hydrographic features

River Thames

The River Thames is a 210-mile English river rising in the Cotswolds and flowing through Oxford and London to the North Sea. Tidal through London with over 7 m spring range, defended by the Thames Barrier, and served by the debt-laden Thames Water utility.

River Torrens

River Torrens (Karrawirra Pari), Adelaide's main river: 85 km from the Mount Lofty Ranges to the sea at West Beach, named by Light in 1836, dammed in 1881 to form Torrens Lake, with highly modified regulated flows.

River Trent

The River Trent is England's third longest river, rising near Stoke-on-Trent and running about 271 km to the Humber Estuary. Navigable from Shardlow, tidal below Cromwell Lock with the aegir bore, it drains 10,450 km2 of the industrial Midlands and supplies about half the Humber's freshwater.

River water

River water is the water carried downhill in a stream bed toward a lake or ocean, supplying drinking water, irrigation, hydropower, transport, and habitat for people and ecosystems.

River Wharfe

River Wharfe: Yorkshire river rising in the Yorkshire Dales National Park, flowing through Wharfedale to the Ouse. Historic Tadcaster navigation; UK's first river bathing water at Ilkley (2020).

Riverland

Riverland Ramsar site (site no. 377), a 30,640-hectare wetland along 80 km of the Murray River in South Australia, listed 23 September 1987; meets 8 of 9 Ramsar criteria, supports 20,000+ waterbirds and threatened Murray cod.

Rivers of Ireland

Rivers of Ireland: over 73,000 km of channels, with the Shannon the longest at more than 360 km. Covers major rivers, EPA hydrometric monitoring, flow regimes, water quality status, and River Basin Management.

Rivers of Jamaica

Jamaica's rivers are more than 100 short, steep, fast-flowing streams organized into 10 hydrological basins and 26 Watershed Management Units; the Rio Minho, at 92.5 km, is the longest.

Roadstead

Roadstead, also road or roads, an area of sea near shore where vessels anchor and transfer cargo with less shelter than a harbor; part of the territorial sea under UNCLOS Article 12, not inland waters.

Roanoke River

Roanoke River: roughly 400-mile Virginia-North Carolina river, also called Moratoc, flowing from the Blue Ridge to Albemarle Sound, dammed by Kerr, Gaston, Roanoke Rapids, and Smith Mountain projects.

Robeson Channel

Robeson Channel (Détroit de Robeson) is a 57-mile Arctic waterway between Greenland and Ellesmere Island, the northernmost and narrowest part of Nares Strait and a major sea-ice export gate.

Rockall Plateau

Rockall Plateau, part of the Hatton-Rockall plateau, a submerged continental microcontinent in the northeast Atlantic west of Scotland and Ireland, separated by the Rockall Trough; its only land is the granite islet Rockall.

Rockpepper Bay

Rockpepper Bay (Ensenada Güemes) is a bay at 63°08'S, 55°45'W on the northern coast of Joinville Island, Antarctic Peninsula, named for its many off-shore rocks and islets; variant name Elsie Bay.

Roebuck Bay

Roebuck Bay (Yawuru Nagulagun) is a tropical embayment at Broome, Western Australia, a 1990 Ramsar site of 34,141 ha with 9 m tides, 160 km2 of mudflats, and over 300,000 migratory shorebirds annually.

Röhss Bay

Röhss Bay is a bay 11 nautical miles wide on the southwest side of James Ross Island, Antarctica, between Cape Broms and Cape Obelisk, discovered by the Swedish Antarctic Expedition of 1901–04.

Roman Baths (Bath)

Roman Baths (Bath): Roman bathing and temple complex at Aquae Sulis, built 60-70 AD around 45 °C hot springs, rediscovered from 1727, museum since 1897, over 1 million visitors in 2025.

Ronge

Ronge: Lac la Ronge, fourth-largest lake in Saskatchewan (1,414 sq km, 364 m elevation), and town of La Ronge on its west shore; fur-trade center, provincial park, dammed since 1966.

Ronne Entrance

Ronne Entrance, formerly Ronne Bay, is the broad southwestern entrance of George VI Sound opening onto the Bellingshausen Sea, West Antarctica. Discovered December 1940 by Finn Ronne and Carl Eklund; renamed as bay ice receded.

Roopkund (रूपकुंड)

Roopkund (रूपकुंड), Skeleton Lake, is a glacial lake at 5,029 m in Chamoli, Uttarakhand, on the Nanda Devi Raj Jat route. Ancient DNA shows three groups: South Asians (~800 CE), eastern Mediterraneans (~1800 CE), one Southeast Asian.

Ross Gyre

Ross Gyre: cyclonic subpolar ocean gyre south of the Antarctic Circumpolar Current in the southwest Pacific, near the Ross Sea. Wind-driven circulation of roughly 20–45 Sv, area about 1.84 million square kilometers, affecting dense-water formation.

Ross Sea

The Ross Sea is a Pacific Ocean bay between Cape Adare and Cape Colbeck, discovered by James Clark Ross in 1841. It is administered by New Zealand.

Røssvatnet

Røssvatnet (Reevhtse) is a regulated lake in Hattfjelldal and Hemnes, Nordland, Norway; after 1950s damming it is Norway's second largest lake at 219 km² and third largest hydropower reservoir, 2.0 TWh, feeding the Røssåga power stations.

RSPB wetland reserves

RSPB wetland reserves are nature reserves of the Royal Society for the Protection of Birds whose principal habitats are wetland, including Minsmere and Lakenheath Fen.

Rubicon

The Rubicon (Rubicone, Latin Rubico) is a small Romagna river, about 40 km long, that marked the Italy-Cisalpine Gaul border; Julius Caesar crossed it with the 13th Legion on 10 January 49 BC, starting the civil war. Its ancient course is disputed between the Fiumicino, Pisciatello, and Uso, with official identification in 1933.

Rukwa (landform)

Rukwa (landform): Lake Rukwa, a shallow alkaline outlet-less rift lake in southwestern Tanzania, in the Rukwa Rift of the East African Rift system; about 3 m deep, seismically active, Tanzania's third largest fishery.

Rupert

Rupert (Rivière Rupert), a major river in western Quebec flowing from Lac Mistassini to Rupert Bay, James Bay; named for Prince Rupert, first HBC governor; partially diverted since 2009 for Hydro-Québec's Eastmain-1-A and Rupert hydroelectric project.

Rushy Lagoon

Rushy Lagoon is a locality and farming property on the far north-east coast of Tasmania, whose floodplain wetland is part of the Flood Plain Lower Ringarooma River Ramsar site.

Russian Arctic islands

Russian Arctic islands: Franz Josef Land, Novaya Zemlya, Severnaya Zemlya, the New Siberian Islands, and Wrangel Island, Arctic Ocean archipelagos totaling over 180,000 km², largely glaciated, depopulated, militarized, and partly protected as national park and UNESCO reserve.

Ruvuma

Ruvuma (Rovuma, Rio Rovuma) is a perennial East African river forming the Tanzania–Mozambique border, about 800 km long, draining a 155,500 km² basin shared with Malawi into the Indian Ocean at Mnazi Bay; a tri-national basin commission agreement was signed in 2026.