Arghûl
The Black Fortress. The Vault of Doom. Hope's Death. These and many other epiphets express the utter dread with which the people of the Flannish Cities regarded the citadel and headquarters of Negroth the Doombringer. From here, his armies marched. Ant to here, his armies brought back both plunder and prisoners, neither of which were likely to emerge again.
Still, it has been more than 150 years since Negroth's fall, and the wilds have slowly began to reclaim the blasted wasteland surrounding Arghûl. The region remains dangerous, to be sure - Negroth and his minions produced many abominations, both alive and dead, and not all have been found and destroyed in the years since. A number of extended orc families live in the region keep watch over it, sometimes coming to the aid of travelers. They also sometimes work as local guides for thrill-seeking tourists and the occasional group of adventurers and archaeologists exploring the ruins. While much has been discovered and cleared, there are always more hidden chambers to be found.
Such expeditions have become more popular as of late. Currently, a number of businesspeople with expertise in the travel business are considering building hotels close to the fortress, as well as a rail line connecting to it. Of course, this would require the region to become safer than it is now, and thus they are hiring adventurers to clean out dangerous monsters - and scholars who can unearth more of the fortress' sordid history.
Designer's Notes
What do you do with Mordor, Barad-Dur et. al. once the Dark Lord is defeated? How about developing it into a tourist trap?