h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Dredging back into the darker recesses of my mind, I think that the great ziggurat of Babylon aka the tower of Babel was called Etaminanki
The major problem with excavating the major cities of old civilisations is that they, like Ankh-Morpork, are built mostly upon their own ruins - that was part of Schliemann's problem at Hissarlik. He assumed that the lowest layer was the Homerian city. Modern scholars do not agree with him - nor do they necessarily agree with each other as to which level, if any, really was Homer's Troy. Deserted sites such as Mohenjo Daro & Harappa seem to raise fewer problems of this sort.