The Codex of Leicester
Leonardo da Vinci's brain overflowed with futuristic inventions, medical insights, and astronomical observations, and the Codex Leicester is where he put it all. The most famous of all his scientific journals, the Codex is 72 pages long and is jam-packed with this famous polymath's assorted mental junk. Because it was da Vinci's personal notebook, the Codex is completely one-of-a-kind. It was purchased by Bill Gates in 1994 for $30,802,500, becoming the most expensive manuscript ever sold. Gates arranges for the Codex to be displayed in a different city every year — maybe your hometown will be next!