Lost cities / archaeology / ancient history

Oliver, there is a book called Collapse by Jared Diamond. I found it to be pretty heavy going, but you're a bit brighter than me so you might go ok.

Great book,
written by a true polymath,
but these guys:

http://longnow.org/seminars/02013/jan/17/statues-walked-what-really-happened-easter-island/

show how easy it is to 'walk' those statues,
meaning much less energy/crops/people were needed than previously thought.