MAP03: Avernus (The Abyss)

MAP03: Avernus is the third level of The Abyss. It was designed by H2SO4, and uses Heretic window textures. It is a marble temple similar to an ancient Roman avernus, or the. The noxious red liquid surrounding the temple is poisonous water that damages the player.

This level is completely non-linear, and the temple's two keys may be obtained in any order, but most players will collect the blue key first.

Walkthrough
Grab the temple's two skull keys, raise the pillars, and make it to the exit. Each key triggers a trap when collected.

Essentials
The first key to obtain is the blue skull key, guarded by imps, a hell knight, and an arachnotron on higher skill levels. There is a special room dedicated to this key that is quite easy to find. The second key is located outside, on a pillar that must be lowered. It is also obtainable when hitting the switch in the blue skull key room.

The last quest is to lower the pillars blocking the exit The switch to lower them is well hidden, and a cacodemon guards the switch at higher skill levels.

Other points of interest

 * 1) The courtyard contains a few powerups in the wall, as well as hidden monsters.
 * 2) The two sheds outside contain monsters and a backpack in coop.
 * 3) There are alternate routes to almost every room except the courtyard.

Trivia

 * The courtyard seems to be in an unfinished state.