1) The Great Barrier Reef in Australia is the largest coral reef system in the world and is visible from space.

2) The Treaty of Tordesillas, signed in 1494, divided the newly discovered lands outside of Europe between Spain and Portugal, leading to the colonization of the Americas.

3) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.

4) The fingerprints of koalas are so similar to humans that they have been mistaken at crime scenes.