Dol Goldur. This place is flipping creepy and unnerving, and you couldn't pay me to go there. (Okay, I might go there with Elrond at my side, but still not willingly.) All those staircases going every which way but not making much logical sense. All the construction. All the spells and illusions. The necromancer, the nazgul, and orcs all in close and twisty confines. No, thank you! Dol Guldur makes Mordor look positively inviting to me.