After the dynasty collapsed, there were no clues as to where it was and it lived on only in legend through writings such as those of 13th century Venetian merchant Marco Polo. If Polo is to be believed, the walls of "the greatest palace that ever was" were covered with gold and silver and the main hall was so large that it could easily seat 6,000 people for dinner. "The palace was made of cane supported by 200 silk cords, which could be taken to pieces and transported easily when the emperor moved," he wrote in his travel journal. It...