Kautilya's Arthashastra 7.11.8

7.11.8

durgādīni ca karmāṇi prabhūtyena kriyante //

Of two watery tracts, one of limited area and conducive to the growth of grains, and another, vast and productive of crops other than grains, the latter is better, inasmuch as it affords vast area not only to grow spices and other medicinal crops, but also to construct forts and other defensive works in plenty: for fertility and other qualities of lands are artificial (kritrimah).