“美国出土”2014/12/20节目的内容如下：

http://www.history.com/shows/america-unearthed/episodes Episodes Season 3

Marco Polo Discovers America

Premiere Date:December 20, 2014 - 09:00-10:00PM ET

Just east of the San Francisco Bay Area are the Berkeley Hills Walls–remnants of a massive stone wall that stretches a distance of over fifty miles. The wall segments are up to six feet high in some places and are constructed of tightly fit limestone boulders. Scott is in intrigued by the fact that nobody knows who built the wall or even what purpose it serves. The only historical precedent for amiles-long, manmade, ancient wall is the Great Wall of China. Could ancient Asiatic explorers have made it all the way to the North American West Coast? In investigating the theory, Scott uncovers other evidence that could suggest the Chinese with their massive maritime fleet made it to the New World, using maps that were in the possession of Kublai Khan. He also discovers evidence that European explorers knew about China's epic voyages, including Italian explorer Marco Polo.

要制造悬疑，此节目一般不把故事讲完，美国人对中国人的贡献也不会特别突出介绍。我只能对自己那片段负责，其他是制作人的主意。实际我的片段大概只占5-6分钟，但是他们起码把宣德金牌和《坤舆万国全图》显示。

根据节目介绍，里面谈到的馬可孛羅地图，大概是我前文讲的。

馬可孛羅的美洲地图?  http://blog.sciencenet.cn/blog-1674084-832109.html

馬可孛羅美洲地图-地图学引出的历史重大翻案http://blog.sciencenet.cn/blog-1674084-832144.html