This enormous stone, found in Russia's Ural Mountains, appears to be a map. The problem with it is that it shouldn't have been possible to make such a map 3000 years ago; it contains details of mountains and rivers, including topographical information that would only be visible from above.
Even the dating of this mysterious item is controversial. Some experts have tested the carvings, and claim that they're 120 million years old. That sounds impossible - but so does making a map like this without the use of a plane.