Since the middle of the 19th century, and for approximately 100 years, the varied mineral resources of the Segura region were exploited in a more or less systematic manner. A mining complex was built in Segura, one of the most relevant in all of the Naturtejo Geopark. Mineral deposits of economic interest occur in association with veins of quartz and barite. These intrusive bodies along fractures originate from an intimate relationship with the presence of granite masses. The tungsten and tin occur in sub-horizontal veins; while lead and barite occur in relation to sub-vertical dominant fracturing, in a NE-SW direction. All of the mining exploitations are currently abandoned, although gold and other geological resources exploration continues. In Segura Mines it is possible to discover an ancient location of mineral plant and casting, by rock piles from the old lead mines and by the old wells of tungsten and tin, all of which comprise unequalled testimony to the evolution of technologies employed for the exploitation of a large variety of mineral deposits of a sub-volcanic nature.