The Dolomites are a mountain range located in northeastern Italy. They form part of the Southern Limestone Alps and extend from the River Adige in the west to the Piave Valley in the east. The northern and southern borders are defined by the Puster Valley and the Sugana Valley. The Dolomites are nearly equally shared between the provinces of Belluno, South Tyrol and Trentino.
Other mountain groups of similar geological structure are spread along the River Piave to the east – Dolomiti d'Oltrepiave; and far away over the Adige River to the west – Dolomiti di Brenta. A smaller group is called Piccole Dolomiti, located between the provinces of Trentino, Verona, and Vicenza.