To see the other 5, carefully jump onto the invisible floor that is on top of the beams next to you, and be careful not to trigger a loading point. The floor of that area is an overlay of the Tri-Gate. Use the Grav-Lift, and have the other person use their Grav-Lift on top of yours. Grenade-Crouch Jump combo onto that beam and walk all the way up (gonna take a while). From there, walk all the way to the end of the platform, until you get to the beginning of the long ass beam that goes up to the top of the map. To get to them, follow the steps above, and then walk to the end of the platform, and VERY carefully, crouch, and then jump off the edge on the right, and attempt to land on the dark ledge. There are 11 known Tri-Gates outside this map, all discovered by General Heed. Walk along this until you get to the end.

Jump onto this and if you die, get your Grav-Lift back.

Walk along them until you can see a little 2D line next to one of them. Drive along it diagonally and you will slip past it and out of the map. When you reach the top, you will hit an invisible wall that can't be boosted through. Keep boosting to get past the invisible walls. Then, go back up to where the tanks and Warthogs came out of before. Once you have a Grav-Lift and a Chopper, make sure you have triggered a checkpoint, or else an invisible wall won't disappear and you won't be able to do this glitch. Get into the building with the Grav-Lifts, and get one, and get a Chopper. To perform this vacation start a Co-op game, and get to the area with the Scarab battle. Disclaimer: I am not liable for any damage done to your Xbox 360 or Halo 3 disc for attempting this glitch. It is a pretty cool glitch in my experience, but there are some gray areas. The Ark Vacation is a glitch that can be performed on the Halo 3 Campaign level, The Ark, that allows you to bypass the normal map boundaries.

Ark how to glitch through walls