There are several ruins of advanced cities that date back even farther. Well over 6,000 years. There is one, the name of which escapes me, where the building methods were so precise that they make the work of the Egyptians look like sand castles. There is another in the Bolivian Andes called Tiahuanacu. Scientists are still debating it's age but most opinions are in the range of 12,000 - 15,000 years ago. It was once a thriving seaport but the nearest water is now 15 miles away and it is over 12,000 feet above sea level. There are also recently-discovered ruins in various undersea locations that range from 7,000 - 9,500 years old. There are also researchers who point to evidence of an even older culture which existed on Antarctica. Who knows how many others are yet to be discovered or have disappeared forever.
