If I had to use an image from the female world, then I would say that the Milan 
Cathedral looks like a piece of lacework - gigantic and at the same time delicate - 
which the hand of a magician has suddently turned into stone. [...] The interior of 
the Duomo is just as beautiful as the exterior. So big and so empty that the soul feels enraptured

Fanny Lewald
Italienisches Bilderbuch
Berlin,1847

The quarries of Candoglia are the beating heart of the Duomo di Milano.

Located in Piedmont, in the North West of Italy, the quarries lie on the Western bank of the Toce river at the border of Val d'Ossola. The marble quarried in Candoglia is exclusively dedicated to the construction of the Cathedral.

The beauty of this marble is perhaps its most surprising characteristic. Unlike other marbles, it is white, pink, green and grey and boasts exceptional physical-chemical characteristics which have had a major impact on the structural and static properties of the monument.

It was Gian Galeazzo Visconti – founder of the Veneranda Fabbrica del Duomo di Milano – who decided to replace traditional milanese bricks - cotto milanese - originally chosen for the construction of the Duomo, with marble. On October 24th 1387 he granted the Fabbrica the exclusive use of the Candoglia quarries. The transportation of the marble was to be free of charge too, along the water ways of the Ticino River and the Navigli designed by Leonardo da Vinci himself for this very purpose.

The conservation of the Duomo is an ongoing endeavor, given the nature of the marble itself, which requires constant and renewed tending to.

Prevention has thus become the underlying rationale in the preservation of this monument: over the centuries, chemical, physical and biological agents have severely damaged the marble. Restoration therefore aims to ensure that future generations can enjoy the Duomo di Milano and take part in the values of faith and art which were at the very heart of its construction.