Between 1970 and 1980, excavations and speleological research in the mine of Saint-Jean Engelsbourg experienced a profound revival. Of the 186 miles of galleries (300 km), only 37 miles (60 km) have been explored. The remains of wooden installations in some flooded areas provided important information on medieval working methods. At the entrance to the mines, the workers used to warm up and store their equipment in the stove house. Ceramic tiles bearing the mines' symbols were unearthed in the rubble.