The Kummakivi Balancing Rock from Finland seems to defy all of physics.

Often, when someone says something is "impossible," they are just referring to something that is exceedingly improbable or difficult.

 You may also, ""What do you mean Jim the pilot has been replaced by an orangutan, and he's even wearing Jim's cap while sipping on a mango daiquiri?

 Nothing could be farther from the truth!" But how many things do we encounter that are utterly irrational? 

Because "impossible" implies "not possible," the answer is "none." It was a pleasure teaching you a little of reasoning.

There are many things to admire in nature, but one of the simplest is nature itself. 

 A waterfall in Cajamarca, Peru, looks like a woman in her wedding dress and veil (via My Modern Met).