A meadow is a possibility.
A large area of treeless grassland can be a plain, savanna or prairie.
plateau or mesa
A plain is a large piece of flat land.
A flat surface; especially, a broad, level, elevated area of land; a table-land., An ornamental dish for the table; a tray or salver.
A large area of flat land or gently rolling land is a bay... There's the answer!!
A plain is a large, flat expanse of land characterized by low vegetation, relatively level topography, and few geological features. Plains can be found on every continent and are typically used for agriculture and grazing.
a plain
Plateau
Plateau
I think this answer is plain.
Plateau
Plateau
I think this answer is plain.
Plateau
Plateau
Plateau