http://www.gamesas.com/topic/1496800-most-recent-things-youve-discovered-4/

The other day, for the first time, I entered Fort Greenwall though the cave that leads up into the well. I discovered it contains one of the largest amounts of glowing mushrooms in Skyrim. There's also a chest and a corpse, with a letter that suggests why he's a corpse. That's a lot of stuff for a location a lot of people might miss.

I knew Clearspring Cave contained the Bow of the Hunt. But when I'd been there before, I missed the Dwarven sword stuck in the ground by a bloody skeleton.

(edited because I thought it was hand-placed but UESP says it's leveled)