Here is a new concept artwork which is rumored to be of an unseen Halo 4 multiplayer map. This immense battlefield is nestled into the cliffs, which sit high above a deep canyon. Two bridges, an upper and a lower, connect the two sides of the UNSC looking structures.
With such a large size it is reasonable to guess that this will be a Big Team Battle map. Remember this is not confirmed, and the design could also have been altered greatly from when this was drawn. Who knows it may not even be from multiplayer, it may be a campaign landscape.
Source: Halouniverse.it and thanks to user Halo 4 Infinity for pointing out the image to me.