Sandbox

Sandbox is upcoming map that will be included in the Mythic Map Pack. Its setting and architechture is similar to Sandtrap, but its forge capabilities seem to be on par with Foundry. The level's hidden skull logo, a Monitor, supports the theory that the map will be Forge based. In certain Bungie.net forum posts, there have been repeated queries as to whether there will be a larger version of Foundry, and in some cases, Bungie staff or higher ranked members have replied and said that there was one in the works.

Sandbox along with Assembly and Orbital have been confirmed to be shipped with the Limited Edition of Halo Wars. Bungie has confirmed they are working to get these maps available on Marketplace as soon as possible after Halo Wars' release on February 27, 2009. The release date for the other three maps is unknown although it is speculated that they will come with Halo 3:ODST.

"Forerunner structures are often so vast, so towering and so exaggerated that they'd be visible from a number of different excavation sites."

- Lukems posted a brief clue about Sandbox's location in the Halo universe on 01.20.2009 2:40 PM PST

This may refer to Sandtrap as it was a desert-based excavation site. It may also refer to the tower of Epitaph as it is very large; and the tower in Epitaph resembles the tower depicted in the sketch of Sandbox, but it could also be one of the Sandtrap towers.

Setting
Sandbox is set in the midst of a barren desert with many rolling sand dunes, similar to Sandtrap. Large Forerunner towers can be seen in the distance. It seems that the map may actually be set on a moon (similar to Halo 2's Burial Mounds), as a crescent shape can be seen in the sky of one of the screenshots. The crescent seems too large to be a moon itself, implying that it is the planet, and the player is on the moon. Bungie hinted that that similar to Sandtrap, the Covenant may have also conducted archaeological excavations here.

Default Sandbox
The default sandbox is perfectly symmetrical, and considered by Bungie to be a medium-large map. It contains two bases opposite each other, with cover laid in between. The map's vehicular arsenal includes a Chopper, Warthog and two Mongooses for each team. The infantry has Rocket Launchers and Missile Pods to counter them, and an overshield is located on top of a pillar in the center of the map. One of the new objects that can be placed in forge are "Kill Balls", which are large orbs that kill anything that goes into it.

Forge
""Sandbox combines large-scale vehicular combat with a limitless amount of Forge customization. Boasting a tiered, open-world layout, “Halo 3” players will be able to build their own unique game experiences using the Forge map editor. Sandbox is a map unlike any Bungie has ever created.""

- Bungie.net

The center of the map is a flat, empty floor, similar to Foundry but visually resembling Sandtrap. The map is built from forge-editable blocks, pillars and ramps. The map is said to include "just about every kind of building block you could ever want", for example tunnels, crouch-only doorways and quarter-pyramids. Sandbox will likely have more vehicles available than Foundry; the confirmed vehicles are Warthogs, Mongooses, Choppers, and Scorpions; and no vehicles were present in the default Foundry. A new Forge item is an orb of light that colors its surroundings in either red or blue; it can be used to differentiate the two bases, similar to most maps made by Bungie. Another is the "Kill Ball" that kills anyone who enters it. Also, when a player goes into editor mode in Forge, a blue-grid appears on the map to help the player place objects straight.

Skull
Sandbox features a hidden skull, the Sandbox Skull. This skull, if obtained, unlocks the Sandbox Skull Achievement. The crest of the hidden skull on this level appears to be a likeness of the Monitor.

Trivia

 * In the new screenshot released by Bungie, Sandbox seems to be a small-medium sized map, possibly about the size of Standoff, with obvious resemblance to Sandtrap. Sandbox may be the desert-theme map of Foundry as the structures within the screenshot are speculated to be scenery objects players can move. Players may possibly be able to change the size of the map and the background too.
 * The vehicles on map, which are the Mongoose, Warthog and Chopper, are the same as Sandtrap, with the only difference having 2 Warthogs less, possibly the respawn times for the vehicles are longer and the land surfaces are more even. There is also two Scorpion tanks that were spotted in the T3.com interview.
 * Upon careful examination of the first screenshot, the boundaries of the map are protected by another Brute mine field as seen before in Sandtrap. You can see the short light warning posts on the left side of the map.
 * It's possible that the Easter_Eggs_in_Sandtrap may also appear on this map because Sandbox has a minefield like Sandtrap and the mines are triggered by faint Sentinel Beams firing from the Easter Eggs. See Easter_Eggs_in_Sandtrap for more information.