Voyages in the east are mostly made to supply settlements on the East Siberian coast, but there is also a certain amount of timber export. Most supplies brought via the Northern Sea Route are destined for various mining enterprises, which produce valuable metals such as gold, silver and tin. Such metals can bear the tremendous cost of mining under Arctic conditions. Gold is mined on the Kolyma fields, diamond in Yakutiya, and tin at Yultin and Pevek. Most of these places rely on river shipping or winter roads which in turn rely on the Northern Sea Route, the Lena river shipping or the Magadan highway.