Further, the municipality of Castro Verde is crossed by the Iberian Pyrite Belt, composed of a massive volcanogenic sulfide deposit (VMS) associated with the polymetallic flanks of volcanic cones in the form of pyrite, chalcopyrite, sphalerite, galena and cassiterite, that begins in Aljustrel, spreads through the lower Alentejo and extends into southern Spain.
During the reign of Sancho II of Portugal, and from 1228 he conducted a military campaign against the Moors in the region of Alentejo, conquering Aljustrel, Alvalade, Juromenha, Beja and Mértola.