Check out these screens from the Spartan Ops mission known as "The Challenge".
The designation “Spartan Ops" has been given to any and all on-record missions conducted by Spartans of the UNSC Infinity. For longtime Halo fans, however, Spartan Ops represents a watershed moment of immersive, story-driven cooperative gameplay delivered in addictive, bite-sized episodic pieces. One of those pieces, The Challenge, takes place on a cold and desolate Forerunner fortress structure, shown in this gallery for your viewing pleasure. Enjoy!