The Sword in the Stone
Bethesda must have a thing for King Arthur, because they've managed to fit in another easter egg that references the legend. If you head south of Rebel's Cairn, you'll encounter a sword sticking out of a pile of stones, Skyrim's take on the famous Sword in the Stone myth.
Sadly, pulling it out won't make you the rightful king of Tamriel (or England, for that matter).