The massive and mountainous chain of the high Atlas Mountains separates Marrakech from the arid plains and semi-Saharan dunes to its south. Rugged peaks rise to over 4,000m (13,000 ft) and are usually snow- or ice-covered from November to April, although in recent, warmer winters they have often had little more than a dusting. With their myriad of remote and friendly Berber villages tucked high up on the plateaux, and the network of mule paths that links them, this region is a walker’s haven, particularly in spring (April-May), when the winter snows have melted, day time temperatures are pleasant, wild flowers abound, and emerald green terraces contrast dramatically with the forbiddingly brown and barren hillsides. Rich in precious and semi-precious stones and crystals, they're also a geologist’s delight.