Foundry

Foundry (Originally coded "Art Vandalay," by Bungie during production) is a multiplayer map released for Halo 3 as part of the downloadable Heroic Map Pack. It was made available on December 11th, 2007. It was made exclusively for Forge, as almost all features of the map can be changed, deleted, or even replaced by any object that Forge has allowed.

Description
There is no set description for Foundry, as it can be Forged into almost any configuration imaginable. Essentially, Foundry is an abandoned warehouse filled with equipment and empty container boxes. The default configuration of Foundry is a mostly close-quarters, two level map with a few long hallways. The power weapons are distributed into the corners and center of the map. The Rocket Launcher is in the center on the second level, there are Brute Shots in each base, and Sniper Rifles are in the corners opposite the bases.

There are two cranes on this map, as well as two shipping areas: A and B. Most of the boxes have "P425" printed on them, indicating possibly that that section of Foundry is Section P425, or it could be a serial number of some sort. It could also be referring to some destination for the boxes.

Getting Out of Foundry
It is possible to get outside of the map when playing the level in Forge. Place a Single Box in front of one of the windows, and put a Crate on top of that. Move the Crate as close to the window as you can. Now place a Machine Gun Turret as close to the window as possible, having it face away from the window and into the room.

Exit Edit Mode and man the turret. Aim as far upward as you can, so that the camera (which is now in third-person view) goes behind the window. Now enter Edit Mode again. You should appear outside of the map.

Once outside, it is possible to place Teleporters, Respawn Points, vehicles, and even Scenery outside of the map. There are two kill barriers outside of the map. If you touch the pipes (or the space above them), or if you walk past the corner of the level, you will instantaneously drop dead. Amusing deaths can result from placing a Warthog so that the passenger seat intersects a kill barrier, and then trying to climb into it. if you try throw a standard grenade into the map when outside, the grenade will get stuck and shake. It will then disappear; if you are near the grenade when it disappears, it will take down your shields.

Strategies
Note: These strategies are for the default Foundry map variant.
 * The forklifts and the trucks can be blown up, and with them, an enemy.
 * The chain link fences can be shot though offering a great way to shoot the fusion coils.
 * Due to the fact that there is a Grav Lift that spawns by default on the original Foundry, it is possible to kill people with Scenery quite easily; such as throwing one underneath a Wire Spool and then fooling someone to step into it.
 * Sometimes you can get splatters in this map if your grenade's explosion force kicks a Wire Spool into the air and it hits someone, though it's very difficult.
 * You can crouch jump out of the windows in the small room of each base. This is extremely useful if you are holding the Oddball, and your defense gets overwhelmed, and you need a quick way out. The crouch jump needs to be precise, or you can get stuck in the window.

Forge

 * Forging along the natural "U" shape of the level is helpful when making balanced and symmetrical maps.
 * It is possible to push a teleporter into the space above the crane nearest to the base area. Doing this will create a great weapon storage space. You can also shoot through the invisible floor at that area. Alternatively, one can simply glide up to this area, face it, and drop a Respawn Point; a Teleporter can be spawned from inside.

Trivia

 * In the trash found on the floor, there is a blue draft notice paper and a pack of cigarettes. In a different pile of trash, there is a purple hippo that is hard to see without aid from the Sniper Rifle.
 * In some piles of trash there is an Origami Crane, if you look for a piece of paper with a Millennium Falcon looking shadow (small) then look about an inch upward.
 * FACTORY CPLX 09 is located on the edge of a lake; opposite the lake there is another factory. If you escape from the "foundry" building and zoom-in on the factory, you should see the words, "FACTORY CPLX 71" on the side.
 * The geographical feature behind factory Complex 71 is a crudely drawn Mount Kilimanjaro seen from the wrong side, or it has at least the same profile. Voi is West South-West of Kilimanjaro, while in Foundry the mountain is rotated so that it is viewed from the south. The mountain has no snow, is too small and too close to Voi.
 * When viewed from inside the level, however, forced perspective may make its side and distance appear to be correct.
 * A Red vs Blue D.I.Y. video was presented using this map.
 * Although some assumed this factory was the one presented in the short Arms Race this is not true as the assembly line in Arms Race is Misriah Armory located on Mars, and Foundry is clearly located on Earth. Also, the factory seen in Arms Race appears larger then the foundry facility.
 * It is possible to fall to your death on this map. You must be in Forge to do this. Place a double box anywhere flat on the ground, then set it to spawn at start: no. Then start a new round. Then go and crouch where you placed the box. When it appears, you will not be able to get out of crouch. Simply move any direction, and you will fall below the map to your death. This can be useful to make "death teleporters" where you place a receiver node under the map and a sender node inside.
 * Art Vandelay, Foundry's codename, is George Costanza's alias in the TV sitcom Seinfeld. Bungie most likely named this map Art Vandelay because George Costanza's alter ego is an architect, and anything on this map can be re-made.
 * Foundry's Forge scenery inventory is impressive - however, it lacks a large amount of items from original maps, such as nearly 50% of High Ground's Scenery (Tire, Telephones, etc.) as well as things like Supply Cases and Comm Nodes (Snowbound).
 * Unknown to many, there is a large cargo shaft above one of the "inlets". A similar hard-to-see shaft is also in the Blue base in Rat's Nest.
 * The description refers to the New Mombasa Space Elevator, which was destroyed before the Halo 3 storyline begins.
 * A poster of the Forge Soccer Ball can be seen pinned up inside one of the chain link fenced off areas with the words "It Glows" underneath it.
 * In random piles of trash there are Chinese boxes with Trogdor the Burninator on it.
 * This map is similar to the warehouse section of the level Floodgate.
 * Just like the other maps in the Heroic Map Pack, Foundry itself also brought along something vehicularly unprecedented: It is the first enclosed map in Halo 3 in which Wraiths can be spawned.
 * A foundry is a factory that produces metal castings.

External

 * Bungie Update.
 * The Heroic Map Pack.