A subterranean river in the Cross Cave system of Slovenia. (Scale shown by people in photograph.)

A subterranean river (also known as an underground river) is a river or watercourse that runs wholly or partly beneath the ground, one where the riverbed does not represent the surface of the Earth. It is distinct from an aquifer, which may flow like a river but is contained within a permeable layer of rock or other unconsolidated materials. A river flowing below ground level in an open gorge is not classed as subterranean.[1]

Some natural rivers may be entirely subterranean, collecting in and flowing through cave systems. In karst topography, rivers that originate above ground can disappear into sinkholes, continuing underground until they reappear on the surface downstream, possibly having merged with other subterranean rivers. The longest subterranean river in the world is the Sistema Sac Actun cave system in Mexico.[2]

Subterranean rivers can also be the result of covering over a river or diverting its flow into culverts, usually as part of urban development.[3] Reversing this process is known as "daylighting" a watercourse and is a major form of visible river restoration. Successful examples include the Cheonggyecheon in the centre of Seoul.[4][5]

Some fish (colloquially known as cavefish) and other troglobite organisms are adapted to life in subterranean rivers and lakes.[6]

Examples of subterranean rivers also occur in mythology and literature.

Natural examples

The cave of source of the Buna can be entered by boat and dived through a cave system serving as an effluence of the Zalomka.
The Puerto Princesa cave can be entered by boat.
Devil's Throat Cave subterranean river from above

There are many natural examples of subterranean rivers. Among them:

Artificial examples

The Effra is one of the subterranean rivers of London. It empties into the Thames by Vauxhall Bridge, from which this photograph was taken.

In many cities there are natural streams which have been partially or entirely built over. Such man-made examples of subterranean urban streams are too numerous to list, but notable examples include:


Some fish (popularly known as cavefish) and other troglobite organisms are adapted to life in subterranean rivers and lakes.

Mythology and literature

The examples and perspective in this section deal primarily with Europe and do not represent a worldwide view of the subject. You may improve this section, discuss the issue on the talk page, or create a new section, as appropriate. (January 2024) (Learn how and when to remove this message)
In Dante's Inferno, Charon ferries souls across the subterranean river Acheron.

Greek mythology included the Styx, Phlegethon, Acheron, Cocytus, and Lethe as rivers within the Underworld. Dante Alighieri, in his Inferno, included the Acheron, Phlegethon, and Styx as rivers within his subterranean Hell. Similar references were made in John Milton's Paradise Lost. The river Alph, running "Through caverns measureless to man / Down to a sunless sea" is central to the poem Kubla Khan, by Samuel Taylor Coleridge.

The characters in Jules Verne's Journey to the Center of the Earth encounter a subterranean river:

"Hans was not mistaken," he said. "What you hear is the rushing of a torrent."

"A torrent?" I exclaimed.

"There can be no doubt; a subterranean river is flowing around us."[12]

Several other novels also feature subterranean rivers.[3] The subterranean rivers of London feature in the novel Drowning Man by Michael Robotham as well as in the novel Thrones, Dominations by Dorothy L. Sayers and Jill Paton Walsh in which a character remarks:

"You can bury them deep under, sir; you can bind them in tunnels, but in the end where a river has been, a river will always be."[13]

See also


  1. ^ William Herbert Hobbs, Earth Features and Their Meaning: An Introduction to Geology for the Student and the General Reader, Macmillan, 1912, pages 182 and 189.
  2. ^ "Underwater cave is the world’s biggest", Mexico Daily News, January 15, 2018, https://mexiconewsdaily.com/news/underwater-cave-is-worlds-biggest/
  3. ^ a b Richard J. Heggen: Underground Rivers from the River Styx to the Rio San Buenaventura with Occasional Diversions Archived 2016-07-21 at the Wayback Machine, University of New Mexico.
  4. ^ Revkin, Andrew C. (16 July 2009). "Rolling Back Pavement to Expose Watery Havens". New York Times. Retrieved 16 March 2010.
  5. ^ Kirk, Donald (2005-10-13). "Seoul peels back concrete to let a river run freely once again". World>Asia Pacific. The Christian Science Monitor. Retrieved 2006-08-21.
  6. ^ William B. White and David C. Culver (eds), Encyclopedia of Caves, 2nd ed, Academic Press, 2012, ISBN 0123838339, p. 468.
  7. ^ "Devon Karst: Karst of the Dinaric Alps - the Dinarides in Bosnia and Herzegovina". devonkarst.org.uk. Retrieved 5 July 2018.
  8. ^ "Devon Karst: Gatačko Polje - GP-Ponor Dobrelji". devonkarst.org.uk. Retrieved 5 July 2018.
  9. ^ "Parque de las Cavernas del Río Camuy - Video Guide - Camuy, Puerto Rico - EyeTour.com". places.eyetour.com.
  10. ^ "Administrative Order No. 29, s. 2012 - GOVPH". officialgazette.gov.ph. 5 September 2012.
  11. ^ ALEXANDER, PAUL B. (1970). "The Reka-Timavo River System of the Yugoslavian and Italian Karst". Yearbook of the Association of Pacific Coast Geographers. 32: 157–165. ISSN 0066-9628. JSTOR 24041059.
  12. ^ Jules Verne, Journey to the Center of the Earth, translated by Frederick Amadeus Malleson, 1877, at Project Gutenberg.
  13. ^ Dorothy L. Sayers and Jill Paton Walsh, Thrones, Dominations, Hodder and Stoughton, 1998, p. 313.