The Apuan Alps, which are called "Alps" because of their morphology, are a mountain range which extends over a surface of 400 square kilometres in the north-west corner of Tuscany. The range is mainly composed of limestone rocks and it runs parallel to the coast, rising up to 1947 metres (Monte Pisanino).

The complex geological history of these mountains began about 220 million years ago, during the Mesozoic era, and is only partly connected with the history of the Etruscan Appennines.

When rising from the bottom of a sea which was covered with various kinds of sediments, these mountains underwent bending, translation, and horizontal and vertical pressure which caused various metamorphic phenomena, creating marble deposits.

Because of their nature, the Apuan Alps show vast examples of karst phenomena caused by the constant action of the weather and, in part, by the succession of glaciations, whose traces are still clearly visible in some places in the range.