The São Domingos Mines in Alentejo, close to Mértola, were abandoned in 1966 after centuries of mining activities.
The area now resembles a post-apocalyptic waste land with its abandoned buildings, lagoons that are full of waste from the mines and as a result have high acidic levels and unusual bright metallic colors and a fascinating barren landscape due to the mining activities, pollution and a general hot climate. It is a beautiful site for those that can appreciate industrial decay.
The town of São Domingos itself has the renovated old mining quarters and an enormous mining pit. More interesting however, is the walk from Santana de Cambas to São Domingos following the old railroad, which is around 15 km round trip, you will very likely be all alone in this barren landscape with these old mining structures along the way and it will be walk you will not easily forget.