The Dolomites are a mountain range located in northeastern Italy. They form a part of Southern Limestone Alps and extend from the River Adige in the west to the Piave Valley (Pieve di Cadore) in the east. The northern and southern borders are defined by the Puster Valley and the Sugana Valley (Val Sugana). The Dolomites are nearly equally shared between the provinces of Belluno, South Tyrol and Trentino.
There are also mountain groups of similar geological structure that spread over the River Piave to the east – Dolomiti d'Oltrepiave; and far away over the Adige River to the west – Dolomiti di Brenta (Western Dolomites). There is also another smaller group called Piccole Dolomiti (Little Dolomites) located between the provinces of Trentino, Verona and Vicenza.
One national park and many other regional parks are located in the Dolomites. In August 2009, the Dolomites were declared a UNESCO World Heritage Site.
The region is commonly divided into the Western and Eastern Dolomites, separated by a line following the Val Badia – Campolongo Pass – Cordevole Valley (Agordino) axis.