Lost cities / archaeology / ancient history

Thanks, that's really fascinating. I read about this going on some time ago but I hadn't seen an official announcement yet. One of my biggest questions is always whether we're not very much underestimating ancient populations, particularly in Egypt, Mesopotamia, and South America, and this is a case in point. It's still incredibly intriguing what happened there--most likely a combination of factors--that caused people to abandon this highly urbanised lifestyle with intense agriculture. Obviously, we mostly only learn of anything with any degree of certainty if we find writings, and while the Maya did write, there is precious little historical writing that's been enlightening, particularly any perhaps explaining aspects of the 'collapse' (if indeed that's a proper word to call it, which it may well not be). It's likely that people who for whatever reason reverted to a less urban lifestyle didn't spend a lot of time writing down/carving into stone the reasons.