Mining in the Masau area was recorded as early as the XVII century, with the first cultivation of lead and zinc. However, industrial activity only started in 1859, with a concession given to the anonymous company of the Montesanto mines.
At this time, new tunnels opened as the older ones emptied. The site saw a succession of different companies managing the mine until the First World War; in 1922, the mine was taken over by a Belgian company, La Vieille Montagne. This company concentrated on the new mining of galena and calamine, minerals which were first selected and then sent to the sieves to extract the lead.
The Belgian company modernised the mining plants, also building Porto Flavia, on the cliff overlooking the sea in order to load the mined material directly onto the ships. Mining work at the Masau mine ended in 1991.
