Only one?! Romania, Dracula's Castle. I was in the valley and saw the castle but it would take 30 minutes to walk up there and they closed in 20... So I would like to go back to that place. One of the best hotel's I'd been too as well, just on the other side of a hill and through the brush. Other places are easier to get to and more common to visit, but that might be my one chance to go back to Romania.