Fortuna Pit Curiosity · Mieres, Caudal, Asturias Image of Mieres, not of the place itself. A shaft at San Andrés which, without ever being worked, became from October 1937 one of the largest mass graves in the country: it is estimated that between three and four hundred people were thrown down its thirty metres. Photo: Meriadoc21 (CC BY-SA 4.0) What to see and do in Mieres