This paper aims to show a new methodological approach to the landscape and population studies, from the consideration of divergium aquarum, a terminus technicus employed by the grommatici. This term has been used to locate confines between pagi and agri. Some specific Latin inscriptions located in summits have allowed increasing this field of research, by giving evidence of the usage of them in ancient Roman times. Therefore, the purpose is to encourage the use of the tools offered by the new technologies to apply this principle of divergium aquarum to individuate probable location of unknown settlements.