The Brenner (1,370 m) is the lowest of all the great road passes across the core part of the main chain and has always been the chief means of communication between Germany and Italy. For some way beyond it, the watershed runs eastwards over the highest crest of the Zillertal Alps, which attains 3,510 metres in the Hochfeiler. But, a little farther, at the Dreiherrnspitze (3,499 m), the chain splits: the main watershed between the Black Sea and the Mediterranean heads south, along the Rieserferner Group to the Dolomites, and Julian Alps.