A great fortification of Vijayanagara was accomplished in the fifteenth century. It also encircled the agricultural heartland and forests. This encirclement had the following advantages:
(i) It enclosed agricultural tracts, cultivated fields, gardens and forests.
(ii) It had an elaborate canal system which drew water from the Tungabhadra.
(iii) In the medieval period, sieges were laid to starve the defending armies into submission. These sieges lasted for many months or many years. So the rulers of Vijayanagara adopted an elaborate strategy to protect the agricultural belt and build large granaries.
(iv) This encirclement also saved crops from animals.
(i) This system was very expensive.
(ii) It was inconvenient to farmers during adverse circumstances.