Djerbian people already exported olive oil during the Roman era. The olive oil mills or maasara, with a very recognisable architecture, were built underground to keep an ideal temperature for the oil fabrication because the harvests were during the winter. People came to the olive oil mill to give their harvest. The olives were crushed by grinding stones operated by donkeys or camels. Then the mixture was put in alfa scourtins (sort of little cakes) that were placed in a pressing-machine. The oil, the first pressure, was collected in jars. Everyone left with the oil that served for the personal use. A few years ago the last underground olive oil mill in Djerba has closed its doors.