I am new to the field of archaelogy so forgive me if this is a naive question, but what are the major cities/sites/artifacts yet to be found? I can see this being complicated by the fact that probably much that is discovered is by chance or wasn't known to exist before its discovery, but are there any major finds people are searching for which are largely believed to exist but are yet to be found? When I consider the vastness of the earth and the time that has elapsed surely there must be thousands of ancient cities/sites buried which havent been discovered yet? If this is so then I hope over time they will be discovered, but is it reasonable to assume we've already discovered most of these sites already? Or is it impossible to predict how much is left to discover due to the very nature of archaeology being about discovering previously unknown facts?