Quote Originally Posted by Karro View Post
Excellent thoughts. I did consider that with Satellite technology, we've essentially taken the mystery out of pretty much everything in our world today....
Even that is not a 100% accurate statement. As an example, take Incan/Mayan/Aztec ruins. Many of these are overgrown so much as to appear as hills to the untrained even while you are standing on them. Many such structures have been found, and I am sure there are hundreds if not thousands left to be found. These sorts of things are impossible to find normal photo satellites. Ground imaging radar/sonar type stuff has a much better shot, but unless you know what you look for, you can still miss it.

My point here is that people tend to see something they are looking for and ignore anything which does not attract attention as being different. Camoflage is a great justification for many things like you speak. Of course, this also neglects other fantasy(D&D anyway) staple concepts such as underground passages connecting various parts of the world. Many in such underground passages, most people still think in standard two dimensions, so it is easy to miss something like the fact that a deep trench having either side or bottom openings which then allow much further movement, after changing the z dimension. Likewise, home many people in a cave with a semi high ceilling miss a man size hole in the "roof", which could very well lead to another whole level.

And as Torstan pointed out... it's pretty darn hard to empirically prove a negative.