The Lonely Mountain
The great Dwarven kingdom under the mountain is an excellent place to visit - assuming they let you in. They probably won't, so don't get your hopes up. Inside the mountain lies the pinnicle of wealth; caverns overflowing with gold and gems. There lies the grave of Thorin Oakenshield, who supposedly still has the arkenstone radiating beside him. Two massive golden statues were recently reconstructed after Smaug destroyed the originals, and their beauty is unimaginable. I would definately reccomend assuming you have a reliable method to get inside.
Credit: Uhan Siddique