The U.S. is home to plenty of archaeological sites, many of which are hidden in plain sight and go unnoticed. Elic Weitzel, an archaeologist and historical ecologist at the Smithsonian National Museum of Natural History, says that's a great shame. "The U.S. is absolutely full of countless archaeological sites, but in most cases you could be standing right on top of one and never know it," Weitzel told Newsweek. Below, Weitzel shares some of his favorite archaeological sites across the country, each offering a glimpse into the lives of the people who lived in North America long before European settlers arrived.