Deathclaw Sanctuary

Deathclaw Sanctuary: Located in the Northwestern region of the map, South - South-West of Fort Constantine, South of SatCom Array NW-05a, between Dickerson Tabernacle Chapel and Broadcast Tower KB5.

Tips

 * A good tip to start with is not to go in there (or just grab the Bobblehead at the entrance) unless you have the skills and spare ammo to use Vengeance in the first place.
 * An extremely useful weapon for fighting deathclaws is the Alien Blaster, as it is extremely powerful (2 or three shots can kill a deathclaw) and quick to reload.
 * The Dart Gun can be very useful here both as a means of silently hitting the Deathclaws and as a means of crippling their legs.
 * Fortunately, the tunnels are ideally suited for stealth play, allowing patient explorers to retrieve Vengeance without engaging any of the Deathclaws. If you have downloaded the new DLC pack (Operation: Anchorage) and completed it, the Chinese Stealth Armor you get is a big help and preserves Stealth Boys. Alternatively, most of the Deathclaws follow paths through some of the narrow tunnels, so it's also an excellent place to combine stealth with mines.
 * If you're having a hard time seeing in the darkness, adjust your brightness. This will let you clearly see everything, and won't give away your position like the Pip-Boy flashlight does.
 * At several parts of the cave you will find a large beam of light from the outside illuminating a pile of bodies containing various loot. It is advised that characters going for the stealthy approach check the surrounding areas first, as these beams will leave you fully visible to any wandering Deathclaws.
 * If you have found Dogmeat already, have him wait outside if you are planning on venturing into the Deathclaw Sanctuary (or any other Deathclaw infested location such as Old Olney) as Dogmeat will intercept incoming Deathclaws and try to engage them in close combat. Three or four hits from a Deathclaw is all it takes to kill Dogmeat.
 * If you are aiming for a non-stealthy approach, it is advisable to bring a follower (except Dogmeat) to watch your back. The Prototype Medic Power Armor can also be useful in this sense, as the armor's on-board computer will alert you if you have been spotted (usually with the lines "Time to kick some ass!", "Gear up soldier!" or "Let 'em eat lead!"). Alternatively, the PMPA announces to the world that you're around (in this editor's experience).

Notable loot

 * There is a locked footlocker right outside the cave entrance which contains various guns, ammunition, stimpacks, and a Duck and Cover! book. There is likely to be a Deathclaw outside the entrance, too.
 * Bobblehead - Endurance directly south of the entry inside the cave, in the first large chamber - on a short pedestal near a pile of corpses and a Rotting Brahmin. (It is to the immediate right at the bottom of the entry slope, ground level) Also in the first chamber:
 * A Mini Nuke
 * A Nuka Cola Quantum - East side of the chamber, on the ground near the Bobblehead - Endurance; look for the glow.
 * A Nikola Tesla and You
 * Vengeance in the far southeast of the caves
 * Jack (Depends on main quest timeline)
 * A fairly rare Roving Trader Hat (+5 to Barter) among the second pile of bodies in the second large chamber in the cavern, east of the entry, straight through a T-junction corridor.

Other loot

 * There's an Enclave soldier that randomly spawns in the cave wearing Tesla Armor, if you haven't cleared the sanctuary beforehand this soldier may be found dead (preyed upon by Deathclaws).
 * There are about seven heaps of corpses and body parts scattered through the cave. Each heap has 2-3 lootable corpses. A couple of the corpses are traveling merchants who have the Trader Hat and Outfit, about 200 caps, and a fair amount of other mediocre stuff.

Bugs

 * On one occasion, on the Xbox 360 version, three Deathclaws were near the entrance when suddenly two of them flew straight up into the air and never came back down. Whether this was an isolated incident or not is unknown. (Confirmed on Xbox 360) it is possible for the Deathclaw to fly straight up from the same spot or a nearby spot if the player waits an hour or two after the Deathclaw initially flies straight up. Also due to the speed at which they are flying, even if you are able to target them in V.A.T.S, your bullets will almost always miss.The same glitch is confirmed in the PS3 version too, The first death claw encountered outside just before you enter the caverns