the northern route
The northern route passes through the Bulgar–Kypchak region. It travels northwest through the Chinese province of Gansu, and splits into three further routes, two of them passing north and south of the Taklamakan desert to rejoin at Kashgar; and the other going north of the Tien Shan mountains through Turfan and Almaty. All of these routes cross high mountain passes to join up at Kokand in the Fergana Valley, and the roads continue west across the Karakum Desert towards Merv, joining the southern route briefly.
One route turns northwest along the Amu Darya (river) to the Aral Sea, through ancient civilizations under the present site of Astrakhan, and on to the Crimean peninsula. From there it crosses the Black Sea, Marmara Sea and the Balkans to Venice, another crosses the Caspian Sea and across the Caucasus to the Black Sea in Georgia, thence to Constantinople.
