It is called a plain.
A large mound or raised area of earth is called a hill or mound.
A large level area with almost no trees is called a plain or a grassland.
A large area where crops are grown is called a farm or a field.
A large area of sand dunes in the desert is called a dune field. A large dune field is called an erg.
An ocean.
a broad area of flat or gently rolling land is called a plain.
A large area controlled by one town is called a city-state.
A large grazing area
a field.
It is called a plateau
they are called layers
plateu