Flat formation is a geological term used to describe a type of landform that is characterized by a flat surface. It is usually formed by the erosion of sedimentary rocks, such as sandstone or limestone, and can be found in many areas around the world. The term 'mesa' is derived from the Spanish word for table, and is used to describe a flat-topped hill or mountain with steep sides. This type of landform is often found in arid regions, such as the southwestern United States.