Here's how to spot false claims and bad archaeology:
- Putting the hypothesis before the evidence. Frequently, authors of bad archaeology create a hypothesis (for example, "Ancient Atlanteans built all the pyramids") and then selectively go around looking for evidence to back up their claims.
- Ignoring part of the evidence. For example, UFO enthusiasts claim that the Nazca lines were landing-strips for UFOs - but then when you see the whole picture, you realise that the alleged landing strips are the feet of a giant bird.
- Deciding that our ancestors were too stupid to invent stuff on their own (so they must have needed help from aliens or Atlanteans to get civilisation started)
- Re-interpreting myths to suit themselves. Instead of legends of gods and goddesses being taken at face value as slightly exaggerated stories of humans or what they actually purport to be - hey presto, they are in fact legends of visits from extra-terrestrials.
- Bad data. Use of old maps, special places, ancient legends, esoteric interpretations of religious writings, instead of excavation reports and historical evidence. In short, bad data.
The point is, real archaeology, which describes how our ancestors actually lived, is far more interesting than bad archaeology. I find the fact that civilisation developed gradually over many millennia and built upon earlier technological and intellectual developments much more satisfying than the idea that some alien being kindly bestowed the gift of fire and writing on Mr & Mrs Ug, who weren't clever enough to think of it for themselves.
Here's some examples of proper archaeology: