Michelangelo's grocery list
This is pretty wonderful: Michelangelo's handwritten, illustrated grocery list. Illustrated, because his servants were illiterate, and couldn't read the words. I often joke about favorite writers, saying I'd gladly read anything of theirs, even their grocery lists. But Michelangelo's list is surely one of the few that qualifies as a priceless relic.
(Via Austin Kleon.)