Heroic Map Pack
From Halopedia, the Halo wiki
The Heroic Map Pack includes three new maps, Standoff, Rat's Nest, and Foundry. It was released at 2:03 AM on December 11, 2007. Originally available for 800 Microsoft Points exclusively on Xbox live Marketplace. Each map presents a totally different play style. There are a handful of new Forge items usable on these maps that were just static parts of the environment on previous maps. These items range from shield walls to man-cannons, to other novelty objects, such as a big soccer ball.[1] The Heroic Map Pack became free to download March 25, 2008[2].
Maps
Standoff
The symmetrical valley of Standoff, with its entrenched bases, fields of boulders and open driving spaces, this map is ideal for mid-sized objective and Slayer game types. There is a secret forge item for this map. Standoff (as well as Valhalla) is considered by some the successor to Halo's Blood Gulch. It was codenamed Jodrell Bank.
Rat's Nest
The vast, labyrinthine passages of the Rat's Nest bring something completely new to the multiplayer experience: an indoor vehicle paradise. Strongly influenced by the Campaign level Crow's Nest, this map is ideal for big team battles and its design makes it perfect for strategy-based games. It is possible to have a scorpion indoors on this level. It was codenamed John Carpenter's Prince of Dorkness.
Foundry
Foundry is the ultimate Forge map. Players can edit every single object in this voluminous industrial warehouse, placing stairways, walls, bridges, and tunnels to create an entirely new play space and build almost any kind of map imaginable. It was codenamed Art Vandelay.
Extras
In all the maps listed, there are all new Forge items, including double boxes, single boxes, fence walls, fence boxes, stairs, walls, wire spools, bridges, dumpsters, doors, trucks, signs, window panels, man cannons, shield doors and soccer balls. They are all featured in the Heroic map pack.