Possible Clues:

• Land ruled by Sauron
• Destination in "The Lord of the Rings"
• Mount Doom's location in 'The Lord of the Rings'
• Middle-earth land that "one does not simply walk into"
• Cursed land ruled by Sauron in Middle-earth
• Sam and Frodo together did finally get gold here
• Realm of Sauron in "The Lord of the Rings"
• Land 'where the Shadows lie' in Middle-earth
• Road into desolate place, wherein is Doom
• Where the One Ring was destroyed