This is the Hub oldtown section of the map of the wasteland presented by:
Oldtown is the best place in the HUB to buy guns, ant the Mitchs gun shop and Drugs at the drug dealers. If you have the missing caravan quest and have talked to beth, go see harold in the lowest lest-hand building. He will tell you an interesting story and tell you bout the Deathclaws. Then go see the crazy man and he will take you to the deathclaws lair:.
You will need a suit of combat armor and a flamer and sniper rifle to kill the deathclaw. Once that is done talk to the mutant and get the holo-disk of him then take it to Butch and the quest is done. If you want to be or are a member of the Brotherhood of steel, go to the closest building to the entrance and kill the mercenaries, then free the prisoner. If you do this you can get some neat Power armor and some other things for the dead guys. You should also go to the thieves circle and talk to them. They are located in the under Biggest building in oldtown. I just killed them. IF you do want to join them you need to steal the necklace from the hightowers.
The theives den: