The site built during the “Monteponi – Montevecchio” management, owes its name to a member of the Sanna – Castoldi family. It is located in Bacu Abis just past the entrance from Iglesias, in the southwestern part of the country. It was built in 1929, and in the next two years the castle, winch cabin and tunnels were constructed. In 1931 it went into operation.
Today, the masonry structure with the m-diameter extraction winch is usable. 1.18, which allowed the transit of two cages. Castoldi Well was active until 1941; it was then used as an ebb and flow route. In the Bacu Abis Mining Concession, mining began in the open pit in 1852, then continued underground from 1915 to 1954, with the Santa Rosa (1915), Emilio (1917), Roth (1918), New (1937) and East (1937) shafts.
