Central Eurasia has been known from ancient times for its horse riding and horse breeding communities, and the overland Steppe Route across the northern steppes of Central Eurasia was in use long before that of the Silk Road. Archeological sites such as the Berel burial ground in Kazakhstan, confirmed that the nomadic Arimaspians were not only breeding horses for trade but also produced great craftsmen able to propagate exquisite art pieces along the Silk Road. From the 2nd millennium BCE, nephrite jade was being traded from mines in the region of Yarkand and Khotan to China. Significantly, these mines were not very far from the lapis lazuli and spinel ("Balas Ruby") mines in Badakhshan, and, although separated by the formidable Pamir Mountains, routes across them were apparently in use from very early times.