The Great Ziggurat
After Commander Keen emerges from The Catacombs he looks up to see that, towering above Kridonea City, is an enormous stepped pyramid. This is the Great Ziggurat, where Elder Caraanae-Augustrus Krislen has taken refuge from the slaughter brought on by the Atroxians. To reach the Elder, Keen must descend into the chambers within the ornately decorated pyramid and survive four challenges. Each challenge guards a gem which will open one of the doors to the Elder's inner chamber, where Keen can hopefully find a way to reach the Sky Sanctum and finally defeat Atroxus!
- Atroxian Realm - Page on this Wiki