You know the stone with the writing where they got the whole 2012 end of the world shit? Well that was found in an area near where i live in Tabasco, Mexico. Well that area is almost gone today for the same reasons, gravel extraction.
The problem is, pyramids are not there to be discovered just like that, most archeological places are buried under tons of shit, sadly most of this archeological places are in third world countries and there's not money to unravel them, they are often found in private land too and sometimes the owners are stupid enough to do things like that.