In the times of Strabo (1st century BC - 1st century AD, during the transition from the Republic to the dictators and the Empire), they were granted as concessions to private exploitation.
En tempos de Estrabón (séculos I a. C. – I d. C., durante a transición entre a República dos ditadores e o Imperio), outorgáronse pois concesións de explotación a particulares.