KF2 Infernal Realm Collectibles: All Relic Locations
Infernal Realm is the hellish themed Killing Floor 2 map with giant gears, caged ZEDs and statues. This guide by a Steam community author lists where to find the collectibles (eyes and relics) in each area of the map; you need at least ten of them for the achievement, but all known spots are shown here, each with a screenshot. See also the Catacombs and Barmwich collectible guides by the same author.
I don't really remember this map in multiplayer, I wonder if it's not at this time that I've stopped playing Killing Floor 2 because of my old computer... Anyway, the map is not one of my favorites. Something is bothering me. But well...

Infernal Relics
Entrance
On the right side
On the giant statue on the left side, in the eye socket
On the left wall, just before the stairs
On the right of the entrance of the "palace"
Further away on the right side, on the rock wall behind a pillar
Balcony with the statue with four arms
On a body in a cage (stairs)
On the left side of the statue
Under a light near the crumbled wall
Room with giant gears
On the top floor, near a ZED in a cage
On the top floor, above the middle cell in front of the stairs
On the middle floor, under a ZED in a cage
On the head of the statue at the bottom left (trader side)
On an inner wall of the center of the room
Before the entrance
In the entrance, on a candelar
Catacombs
On the rock wall on the right side (coming from the giant gears room)
On the rock wall in front of the previous collectible
Further away, on a candelar
In a tunnel
In the bloody corners in the stairs leading back to the entrance
On the praying statue, in the passage leading to the bottom balcony
Bottom Balcony (gears in front)
On the wall near the cage
On a candelar, near the unavailable door
Balcony with Praying Statue
On the Praying Statue
In the bottom passage
Next to the balcony, at the extreme end
On the sort of arch
On the crucified body
Stairs connecting Praying Balcony and Four Arms Balcony
Behind the destroyed door, on a praying statue
On one of the niches
Source
Based on the Steam community guide by Vic=HKC= (CC-BY-NC), published 27 May 2023.