Old Silk Road
From Tardis Wiki, the free Doctor Who reference
The Old Silk Road was a route along which commerce and culture had travelled to and from Cathay for thousands of years. Yarkand marked the beginning of the road, when travelling from the west. The First Doctor, Susan, Barbara, and Ian joined Marco Polo's caravan as they travelled along the road to Shang-Tu. (TV: Marco Polo, PROSE: Marco Polo)
