Features

• Gorges are usually very deep and narrow, formed from the movement of water or lava. Many gorges have walls of sandstone or granite, although there are some very complex gorge systems that are carved into limestone; erosion here can produce intricate cave systems throughout the rock.
  
  

Geography

• Gorges can be found across the globe, from Australia to Morocco to the United States. Many of the more impressive gorges are located in arid parts of the world, like the Grand Canyon of Arizona.
  
  

Canyons on Other Planets

• Gorges can be found on planets besides Earth, although their method of formation may be different. On Mars, the Valles Marineris is generally considered the largest canyon in the solar system. It was likely formed by a rift fault that had been eroded by the decompression and liquefaction of carbon dioxide.
  
  

Underwater

• Submarine canyons are common features connected with major river systems, such as the Amazon and the Congo Rivers. They form on the sea floor bordering a continental shelf, and can occur because of volcanic/seismic activity or due to turbidity currents.
  
  

Tourism

• Gorges are popular tourist spots, especially for rock climbers and spelunkers. Some of the more common destinations include Red River Gorge in Kentucky, Todra Gorge in Morocco and Cheddar Gorge in Somerset, UK.
  
  

Formation

• Gorges usually take thousands or even millions of years to form, but this isn't always the case. Take the Canyon Lake Gorge in Texas. In 2002, massive flooding over a period of three days cut a swath of land 1.5 miles long and 80 feet deep in spots. The flood tore off vegetation and grass and exposed limestone that hadn't been seen for millions of years.