The working of the Candoglia Quarries for supply of the marble for the Duomo of Milan is a complex activity which is managed in all phases by Veneranda Fabbrica, which has always paid great attention also to the aspects connected with knowledge of the territory.

The detailed studies of the morphology and geological-environmental characteristics of the individual extraction locations form the essential basis for best carrying out the excavation. In order to acquire precious and essential information, research and survey campaigns are periodically promoted. 

The image shown here refers to a particular inspection of a shaft of the Cornovo quarry which was performed by the Piedmontese Speleological Group  in 1966 and forms part of a report which the Group was asked to draw up in order to ascertain the characteristics of the cavity, carry out surveys and at the same time conduct the corresponding petrographic and mineralogical investigations.