There are actually a few places where the hide-from-view things works. The Grand Canyon is one of them. I went there once, across a whole lot of semi-arid, flat scrubland, and then suddenly there's a mile deep, nine mile wide, several hundred mile long, great big gap in the ground. Just a few dozen feet away. Whoops, how did that get there?

I wonder if it's actually some cunningly secret military cloaking device, and the US military decided to test it on the Grand Canyon first?