The Angelic Ruins is modelled after The Descent, featuring numerous Eridian stone blocks that provide scattered cover and create elevated platforms that can be scaled. There is higher ground in the form of a hill near the centre of the arena, although it is generally unwise to attempt to make a stand there as cover is sparse and players will often find themselves open to fire from all sides. As with all of the Underdome arenas, there is a large, curtained stage that dominates one side of the map and acts as a spawn point for any boss characters.
The Angelic Ruins spawns Human (Lance and Bandit) and Guardian enemies. Skags do not appear. The enemy spawns in the Angelic Ruins tend to give Siren and Hunter class players a better role to play, since Sirens specialise in elemental skills and Hunters can simply circumvent the tough shields used by the Guardians
- In general, it is best to stay near the spawn point, specifically in the dense and jumbled ruins next to it, as much of the rest of the arena is open and largely devoid of dependable cover. This is also a good place to be during the Boss Wave as a large passageway through the ruins will give a clear line of sight on the stage, and most Boss Wave enemies will simply charge straight at the player, making them easy targets.
- Two man-made platforms in the northern recessed area, overlooking the spawn point, make for good sniper's nests, although enemies will sometimes spawn on the ground in between them, allowing them to quickly flank the player(s) and attack from behind. It is also possible to become trapped by swarms of Psychos and Midgets during Horde Waves; in such an event leaping over the side of the platform offers the best chance of escape.
- As with all the Underdome arenas, the challenges (specifically the larger challenge) can be completed much faster by playing in splitscreen with a low-level character as the host and a high-level character as player two; all enemies will level to the host character, making them easy targets for the second player.
- There is an inaccessible munitions vendor located behind a pillar outside of the map's boundaries.
- Sometimes if the player kill the horde waves too fast then 2 waves will spawn at a time. This is because there are no enemies on the screen so the game will think the wave is over but still spawn enemies from the other wave