Anyone have a place they haven't been to yet?

I've been playing off and on since launch, only becoming a regular player last year. 700 levels into the game and I've never been to the Ohio River Adventures. I've been in the TNT domes, I've been in the Sugar Grove blacksites, I've been to every hidden corner of the map, except for Ohio River Adventures. I don't know why either. I'm afraid of loosing the last remaining mystery in Appalachia. Am I alone in this or do any of you guys have a place you're avoiding?