BASIN

a large or small depression in the surface of the land/ocean floor.

BAY

a coastal body of water partially surrounded by land.

BUTTE

an isolated hill with steep, often vertical sides and a small, relatively flat top. Smaller landform than mesas and plateaus.

CANYON

a deep, narrow valley with steep sides.

CATARACT

a descent of water over a steep surface; a waterfall.

DELTA

a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water.

FLOOD PLAIN

a generally flat area of land next to a river or stream.

GLACIER

a huge mass of ice that moves slowly over land.

HILL

a landform that extends above the surrounding terrain. Often has a distinct summit.

ISLAND

any area of land smaller than a continent and entirely surrounded by water.

ISTHMUS

a narrow strip of land connecting two larger landmasses and separates two bodies of water.

MESA

a flat-topped mountain or hill; a wide, flat, elevated landform with steep sides.

MOUNTAIN PASS

a route through a mountain range or over a ridge.

MOUNTAIN

a large landform that rises above the surrounding land in a limited area, usually in the form of a peak.

PENINSULA

a piece of land that is bordered by water on three sides but connected to the mainland.

PLAIN

a flat, sweeping landmass that generally does not change much in elevation. Plains occur as lowlands along the bottoms of valleys or on the doorsteps of mountains, or as coastal plains, and as plateaus or uplands.

PLATEAU

a flat, elevated platform that rises sharply above the surrounding area on at least one side.

RIVER MOUTH

the place where a river enters a lake, larger river, or the ocean. A delta may be formed at the mouth of a river.

STRAIT

a narrow body of water that connects two larger bodies of water.

TRIBUTARY

a freshwater stream that flows into a larger stream, river or other body of water. The larger, or parent river, is called the mainstem.

VALLEY

a low area between hills or mountains, typically with a river running through it.

VOLCANO

an opening in the Earth’s crust that allows molten rock from beneath the crust to reach the surface. This molten rock is called magma when it is beneath the surface, and lava when it erupts or flows from a volcano. Along with lava, volcanoes release gases, ash and rock.