Mountain- A large natural elevation of the Earth's surface, usually with steep sides.

Hill- A raised area of land, smaller and less steep than a mountain.

Plain- A large, flat, or gently rolling area of land with few changes in elevation.

Plateau- A flat, elevated area that rises sharply above the surrounding land.

Valley- A low area between hills or mountains, often with a river running through it.

River- A large stream of water that flows across the land and into a lake or ocean.

Lake- A large body of water surrounded by land.

Ocean- A vast body of salt water that covers most of the Earth's surface.

Sea- A smaller body of salt water, partly enclosed by land, connected to an ocean.

Gulf- A large area of sea or ocean partly enclosed by land, larger than a bay.

Bay- A smaller body of water partially enclosed by land, usually with a wide opening to the sea.

Island- A piece of land completely surrounded by water.

Peninsula- A piece of land almost surrounded by water but still connected to mainland.

Desert- A dry, barren area of land with very little rainfall and sparse vegetation.

Forest- A large area covered chiefly with trees and undergrowth.

Glacier- A slowly moving mass of ice formed by snow accumulation over time.

Delta- A landform created by sediment deposited at the mouth of a river.

Canyon- A deep, narrow valley with steep sides, often carved by a river.