| ||本文介紹的是地表上的隱蔽山谷. 關於關於鋼鐵兄弟會莫哈維分部基地的未標記地點，參見隱秘山谷地堡。|
|“||Scavengers report hulking individuals moving around Hidden Valley after dusk, but have been unable to identify them due to low visibility.||”|
Hidden Valley is a complex of USAF bunkers remaining from before the Great War near the heart of the valley. Abandoned even before the war, the area around the bunkers is littered with junk. Signs on the roads and peaks leading into the valley mark the boundaries of the complex. Stretches of drooping pre-War wire fences also note the area as being USAF restricted. Prospectors who have returned from Hidden Valley have reported four bunkers, each with an intercom system, but complete silence in response to any calls on the intercoms. Furthermore, prospectors have reported an eerie feeling upon entering the complex. Others tell of seeing armored figures exiting the Valley from within a raging sandstorm that seems to arrive every evening and stay for the night.
沿著斯隆恩附近的路可以抵達隱秘山谷。山谷鐵絲網的西北和東南都有口子能進來。還有幾條小路也通這裡。其中一條經過毒蠍峽谷，顧名思義，裡邊蠍子超多，大多是變異木蠍，偶爾有巨型輻射蠍。.A hollowed-out rock with a heart and anti-bomb symbol painted on it will be directly in front of the player character when fast-traveling to Hidden Valley.
If the Courier entered the west bunker (below) without Veronica as a companion, they will be assigned a task to remove an NCR ranger from this bunker. After dealing with the ranger OR making contact using Veronica OR answering the summons for ED-E, a trip-wire triggering the grenade bouquets will appear in the entry room door, along with more entry room grenade bouquets (one to the left is disarmable). The entrance hall grenade bouquets previously mentioned will also respawn if disarmed earlier.
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- 如果沒有激活任務「Still in the Dark」南掩體空無一人。激活後，火堆旁邊會冒出一個NCR遊騎兵。
- 如果使用口令進入兄弟會基地，會立刻激活「Still in the Dark」中的NCR遊騎兵部分，同時武器和裝備被拔個精光，直到完成該任務才歸還。你還是提前存個盤把。
- 如果是靠著撬鎖技術進來，裡面的人倒是不會打你。不過，出去的時候就麻煩了，你的小弟們都出不來了。要麼你再撬鎖進來接他們，要麼完成「Still in the Dark」再來找他們。
- In the south bunker there are grenade bouquets hanging from both the ceiling at the bottom of the staircase, and in the center of the main room. If entering the bunker after receiving the related task as part of Still in the Dark, the traps will be gone.
- The interior of the Brotherhood's bunker bears a striking resemblance to Raven Rock from Fallout 3.
- Four Brotherhood of Steel paladins will regularly go out on patrol between 1am and 3am, guarding the area near the bunker until just before dawn. If they are encountered leaving the inner bunker you will be forced to start the Still in the Dark quest, unless the player has Veronica in their party. If the player talks with them at this point, they will speak as if the player is already a member of the Brotherhood. If the player dismisses Veronica at this point, the paladins will turn hostile.
- There is a hollowed-out rock in the middle of Hidden Valley.
- Most of the time it will be hard to fast travel when inside Hidden Valley because of the bark scorpions in the area.
- pc ps3 xbox360 在遊覽完畢從掩體里出來的時候，你眼前會刷出2-5隻變異木蠍。表達式錯誤：未預料的<操作符
- ps3 pc xbox360 從斯隆恩到山谷的小路上，可能會碰到從採石場跑出來的死爪，沒準還有超狠的阿爾法死爪，而且是突然蹦出來。表達式錯誤：未預料的<操作符
- ps3 xbox360 If fast-traveling to Hidden Valley and arriveing just before sunrise, the ground may turn black and the distant surrounding areas will turn into a hazed green. The ground will eventually change back into color, although the screen will turn completely black afterwards, and the game will need to be restarted. A way to avoid this is leaving Hidden Valley before the screen changes. This is most likely a glitch from the sandstorm that flows throughout the area at night.表達式錯誤：未預料的<操作符
- This may also occur if the wait function is used while in Hidden Valley.表達式錯誤：未預料的<操作符
- pc 掩體里可能刷出一個馬克一型機器守衛，專門堵路。表達式錯誤：未預料的<操作符
- pc xbox360 Sometimes an evolved centaur will spawn right next to the player character upon fast travel to Hidden Valley. This can begin to happen after killing Moe and the other various centaurs in the crater near Black Mountain.表達式錯誤：未預料的<操作符
- xbox360 It is possible to get infinite ammunition from the supply footlocker. By using the ammunition to craft something in level two and then returning, the footlocker will be resupplied. Simply exiting and re-entering the bunker will also respawn more ammunition.表達式錯誤：未預料的<操作符
- ps3 It is possible to go through the ruins blocking the entrance to the bunker. It is impossible to leave once inside, however.表達式錯誤：未預料的<操作符
- xbox360 Victor can spawn in the bunker when waiting by the ammunition case.表達式錯誤：未預料的<操作符
- ps3 During the tutorial quest, Sunny Smiles may transport to the valley.表達式錯誤：未預料的<操作符
- pc xbox360 When approaching the valley at night when cateye, or with the Friend of the Night perk, the night vision effect will suddenly fail and the screen will become much darker. This can happen at a distances well over 100 yards away and can be surprising when coming from directions where the valley itself cannot be seen. This may be an effect of the camouflage system, and can be fixed by simply walking in another direction.表達式錯誤：未預料的<操作符
- xbox360 When killed, the bark scorpions may glitch through the ground and disappear sometime later.表達式錯誤：未預料的<操作符
- xbox360 pc When disarming the grenade bouquets in the south bunker while using Turbo, sometimes they can be successfully disarmed (adding the three grenades into the inventory), yet the trap will still trigger, dropping three more exploding grenades.表達式錯誤：未預料的<操作符