Since the mid-20th century, the Mesas do Castelinho has been a point of reference in the archaeological mapping of southern Portugal. It was occupied at an early date, and its heyday coincided with the Roman presence in these territories between the 2nd and 1st centuries BC, when it controlled routes connecting the Algarve with Alentejo, taking advantage of the course of the Guadiana and the passes through the Serra do Caldeirão. The excavations have recovered many coins consistent with the profile of the rest of the archaeological material recovered there.
Roman denarii and asses are complemented by bronze coinage from Murtilis, as well as from other mints in the south of the Iberian Peninsula (Gadir) and the Guadalquivir valley (Castulo). A group of monetiform leads from Ossonoba is made outstanding by its size and distance from their centre of issue; there are moreover some uncertain issues possibly of a local origin.