We learn from the writing of Marco Polo in his old age as he recalls the exploits that he and his father and uncle experienced in their years long adventure journey between Venice to Cathay and return. Dressed in rags yet hiding silken riches inside their beggars clothes, they left with diamonds and gemstones to trade for silks and spices and returned with abundant rewards for their years of efforts. Yet the Polo family missed the first portion of the Silk road, that is, the Damascus to Mount Ararat portion.
This Silk Road was the first or last trade road from the southern portion of the old Roman Empire had Damascus as its western terminus. Thus Damascus was truly the western hinge of civilization and is today the oldest continually inhabited city on earth. Ten thousand year old Jericho nearby was earlier but is now an uninhabited plateau in contrast to the busy industry nearby. Hence Damask is finely woven silk from the Silk Route running over the top spine of Asia into mysterious Cathay and their fabled, sacred protected under threat of death silks.
If the Polo family knew of this route that predates their 1200 AD journey by centuries, they made no use of this Silk route. At least they only made use of the Silk Road when their ship from Venice parked them at the eastern shore of the Black Sea. While the original west meets east Silk Road extended east from Damascus and up around the legendary Mount Ararat of Noah’s Arc fame, and continues north east and upward.
This huge bulge of Asia is the platform for the mighty Himalaya Mountains, and the Silk Road extends back down into the Gobi Desert, where seldom could be found any silk worms of Cathay fame. Only as southern arms of the Silk road branch off to your right down into southern silk plantations, unseen in the colder north. The mighty river that divides the climate of China with its route from the central plateau to the Pacific Ocean, wheat and grains to the north of the Yangtze River, rice to the south of the Yangtze River.
The Polo family needed special permission to visit faraway regions of China as well as spies as escorts from the Emperor. Mighty Khan could guarantee, which he did, after all forms of Polo kowtows of deep bows of deep respect were given. To try to allow any foreign eyes to learn of a state secrets such as the silk worm and its life cycle was to put a quick end to your own life if found out. China knew silk and fire works were a valued secret, and the exporting of silk worms did not happen quickly.
Marco Polo may have instigated part of the reason why a church bell on the Dalmatian Coast not too far from Venice was stuffed with the new firesworks and large rocks and used to blast down a castle wall. In this way, Europe welcomed in the days of gun powder.