Economic Forecast
If the Seven Wonders of the Ancient World were not limited to the Mediterranean region, the Great Wall of China would likely make the list. The one that made later lists was mostly built in and after the 14th century but prior walls were built as far back as 200BC. Defending against Mongol raids was the most obvious purpose but trade and immigration control were also reasons why the Han Dynasty built the early earthen barriers so that workers and goods were accounted for and taxed.