Antonio Stradivari, the celebrated maker of violins, made two guitars. (Two, I suppose, that are documented and known to be his creations?) And this is the exquisitely crafted sound hole of one of his master creations, a guitar known as the Rawlins:
More pictures at the University of South Dakota's National Music Museum page, where the instrument now resides. Click, drool, wipe, repeat.
(Anybody know if the museum has a "NO STAIRWAY TO HEAVEN" warning sign?)
UPDATE: Puppy Manohar: In response to your question about 5-stringed guitars, I came across this terrific page on the evolution of 19th century guitars. You may want to look it up. That site even has a picture of Rawlins' headstock (scroll down the page.)