As the original Renaissance Man, Leonardo da Vinci did it all; the polymath was interested in everything from art to science to writing. The famous Renaissance artist's paintings, sculptures, and architectural achievements are as stunning as his intellectual contributions to history, anatomy, and mathematics. One of the areas where Leonardo truly excelled was inventing. While observing the world around him, Leonardo took copious notes and made sketches detailing his surroundings. In the process, he came up with practical and impractical mechanisms alike, many designed to be used as tools of destruction.