The Silk Road
In 629 – 645 the Chinese traveler and Buddhist monk Xuangzang crossed Central Asia on his way to India. Those were the times when diplomatic, trade and cultural relations between China and Central Asian countries were at their zenith. The Chinese pilgrim gave account of his trip in his book ‘Da Tian Si Yun Tsi ’ (Notes on Travels about Western Territories during Rule of Great Tang Dynasty in China). It was the first known “guidebook” to the cities of our forefathers. In his book Xuangzang narrated about the prosperous country Sogd and its capital Samarkand, about Chach (Tashkent), Ferghana Valley, Ustrushan, Kesh and Tokharistan (Bactria), which all were then situated within the territory of today’s Central Asia.
In Europe the earliest ever known “guidebook” to the Great Silk Road was the manuscript written 700 years ago on the basis of Venetian trader and explorer Marco Polo’s account of his travels, in later period known as “Book by Marco Polo”. If you are interested about Marco Polo's book then you can order it here.
More about the Silk Road is available on Wikipedia.