Kautilya's Arthashastra 10.4.3

10.4.3

samā sthirābhikāśā nirutkhātinyacakrakhurānakṣagrāhiṇyavṛkṣagulmavratatī.stambhakedāraśvabhravalmīkasikatāpaṅkabhaṅgurā daraṇahīnā ca rathabhūmiḥ, hastyaśvayor manuṣyāṇāṃ ca same viṣame hitā yuddhe niveśe ca //

That which is even, splendidly firm, free from mounds and pits made by wheels and foot-prints of beasts, not offering obstructions to the axle, free from trees, plants, creepers and trunks of trees, not wet, and free from pits, ant-hills, sand, and thorns is the ground for chariots.

For elephants, horses and men, even or uneven grounds are good, either for war or for camp.