Halo 4 isn't all Master Chief and his revamped blue buddy. It's also got giant, uninhabited spaces with incredible views, as seen in the two Xbox Live Marketplace "Premium Themes" that Little English Halo Blog snagged.

The vista above - full of upside down buildings hanging precariously over a mountain range and marked with a UNSC shuttlecraft of some form - seems to be a Forerunner world of some form, but we can't be sure. As for the second screen, it looks like an engine room, but then we're not exactly future engineers.