Friedman said he saw a cloud of dust hang in the air where the structure once stood.

弗里德曼表示，自己在望远镜曾经矗立的地方看到空中飘浮着一片尘土。

These giant earthworks served as the foundations of what were likely some of the tallest standing structures in North America.

这些巨大的土方工程可能是北美一些最高的立式建筑的基础。