Quarantine Zone vacation

The Quarantine Zone Vacation can be done on the Halo 2 level, Quarantine Zone.

Walkthrough
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 * As soon as the level begins, turn around. You should see a tunnel leading off to the area you just came from. Head down that tunnel, as if you were going to get the Sputnik skull. Then, when you come out of the tunnel, head towards your left, towards a wall. You'll notice (if you're in the right spot) that there are lights on the ground, and in front of one of those lights, one on the very end, there's a tree. Get on the light, and jump onto the tree's lowest branches. After you land on the first, jump up to the very top branch, and then go as far as you can on the branch. This may require some practice to get right. Next, turn towards the wall that the lights are shining on, and jump on top of it (you may need to do a crouch jump). If you did it right, when you walk forward a bit more, you should see the area where you were when you began the level. Now you can go wander the mountains of Quarantine Zone.
 * When you get into the "elevator" part of Quarantine Zone, get to that area thats in the middle of the elevator, then wait until you get into that BIG dark room, and when you see the first platform place, jump onto it at just the right time, then go to the back of it and jump carefully onto the bar holding the platform up, and walk down onto the strip that the elevator was hovering above, then if you jump down carefully you can reach the dark area at the very bottom of the room.
 * Do the same as the above except don't jump off the elevator until you go past that big room, then jump onto the platform when you enter that tunnel right after the dark room, then jump onto this bar thing to the right of it, then you should be right in front of that big circular door thing (but the doors missing), jump onto it while going left slightly, you should slide onto the bottom of the door, then fall off of it and you should be in this large corridor. Now see if you can find the secret room in this corridor.