Some of the most mysterious ancient artifacts ever ... protected and requires special permission to visit. Many ancient Mayan city ruins across Central America are open to the public.

This mountain city in Bulgaria is known as the Machu Picchu of Europe but is less crowded and easier to get to, while still full of ancient mysteries.

Minecraft fans have always been made to speculate about the game - the developers have intentionally not given many answers so that the world remains full of mystery.