In chapter 5 of Doom: The Dark Ages, one of the main challenges is called “Countercult”, where you must find and destroy all three Cultist Circles.
It comes with several mission challenges that reward players for exploring and completing secret tasks.
This section of the game focuses more on puzzles and secret areas than heavy combat.
Destroy All Cultist Circles In Doom Dark Age
To complete the Countercult challenge, you must find and destroy three Cultist Circles, which are located in hidden areas throughout Chapter 5.
First Cultist Circle is found in a secret Landing Zone below the central circular platform in the middle of the city.

To access this area, you first need to defeat two Titans guarding the zone. After landing, go to the lower level where you’ll find a mostly quiet puzzle area.
The Cultist Circle is in this section. The Second Cultist Circle is located on the rightmost Hell Carrier in the city.
First, disable the turrets and land on the carrier. After clearing out the enemies, head to the Sentinel Shrine courtyard.
Look to the right and find a path marked with gold between two buildings. Follow it into a hole and into a cave to find the Cultist Circle. This area also has 64 gold and a secret.

This final one is near the leftmost Hell Carrier. After getting the Super Shotgun, go through the next hallway.
Use your Shield Throw on a metal chain above a green switch to open a path.
Go through the new gate, push a crate, climb it, and drop down to find the last Cultist Circle. Nearby, you’ll also find a Codex entry and some gold.
Completing this challenge gives you 1 Ruby, and is automatically done if you’re following all collectible and secret locations.
Land At Two Secret Zones
The Layover challenge asks you to land your dragon at two secret Landing Zones.
First Landing Zone: Head to the south of the flight area. A Titan with a cannon is standing on one of the spires.

Kill it, land, destroy the tree, and defeat all demons. After that, go below the area to find gold and a chest with more gold.
Second Landing Zone: This one is below the central Hell Carrier, in the same chasm where you find the first Cultist Circle. Kill the two Titans here to unlock the Landing Zone.