You’re standing at the edge of a glowing, triangular vent deep under the earth. Below you, a massive mechanical arm swings a half-finished Shell-snapper through the air. The hum of the machine core is vibrating in your teeth. This is a Horizon Forbidden West cauldron, and honestly, if you haven’t felt that slight sense of claustrophobia while navigating one, you aren't playing it right.
These subterranean factories are the literal heart of the game’s world-building. They aren’t just "dungeons" in the traditional RPG sense. They are the production lines of the apocalypse. While the first game, Zero Dawn, introduced us to these neon-lit labyrinths, Forbidden West turned the dial way up. The puzzles are more vertical. The boss fights are tighter. The stakes feel higher because, let's be real, some of those overrides are basically mandatory if you want to survive the late-game trek through the Forbidden West.
Most players treat a Horizon Forbidden West cauldron like a checklist item. You go in, you parkour for twenty minutes, you kill a boss, and you leave with the ability to ride a new robot. But there is a layer of mechanical complexity and environmental storytelling here that most people breeze right past. If you’re just rushing to the core, you’re missing the actual point of why these places exist in the lore—and you're probably making the combat way harder than it needs to be.
Why Everyone Struggles With Cauldron MU
MU is usually the first "real" one you hit. It’s located in the mountains south of Plainsong. It’s the introductory course to how HEPHAESTUS has upgraded his security since the first game. You’ll notice the vents are more aggressive. The platforming requires better timing.
The biggest mistake? People forget to look up.
In MU, the verticality is a teacher. It’s showing you that Aloy’s new movement tools—specifically the Pullcaster—are not just for world exploration. They are combat tools. When you’re facing that Wideweather at the end, the arena is designed to be used. If you stay on the floor, you’re dead. You have to use the grapple points. It’s a shift in mindset from the relatively flat arenas of the first game.
Also, can we talk about the arm? The giant mechanical arm moving the containers? That’s not just scenery. It’s a timing puzzle that tells you exactly how the "life" of a machine begins. You’re seeing the assembly line. It’s industrial horror disguised as a sci-fi playground.
The Absolute Nightmare of Cauldron IOTA
If you want to talk about a Horizon Forbidden West cauldron that actually changes the map, it’s IOTA. Located at the northern edge of the map, near the Scalding Spear region, IOTA is special. It’s broken.
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When you get inside, you realize the Tallneck—the giant satellite-headed machine we all love—is stuck. It’s half-built. The factory floor is jammed. This is peak Guerilla Games storytelling because it integrates a world activity (mapping the area) with a dungeon crawl. You don’t just "clear" IOTA. You repair a god.
The boss fight here is a Rollerback. It’s fast. It’s annoying. It’s basically a giant armored armadillo that wants to flatten you into a pancake. But the real challenge is the escape sequence. Once you override the core, you have to ride the Tallneck as it’s being raised to the surface. It is one of the most cinematic moments in the entire franchise. It’s also where many players realize that the cauldrons aren't just isolated bubbles; they are physically connected to the crust of the earth. When that Tallneck finally steps out into the sunlight, the map reveals itself. That’s organic progression.
Getting the Overrides Right (The Part Nobody Explains)
Here is a frustrating truth: clearing a Horizon Forbidden West cauldron doesn't always give you the machine override immediately.
I’ve seen so many people complain that they finished a cauldron but still can’t override a Stalker or a Scorcher. Look at your crafting bench. Guerilla added this mechanic called "Corrupted Overrides." Basically, the cauldron gives you the recipe, but you still have to go out and hunt specific machine parts to "finish" the override at a base workbench.
It adds a layer of grind that some people hate, but it makes sense. HEPHAESTUS is evolving. He’s encrypting his creations. You have to work for it. If you’ve cleared Cauldron CHI and you still can’t hop on a certain machine, check your "Special Gear" or "Quest Items" tab. You’re likely missing a circlet or a primary nerve.
The Cauldrons You Can't Afford to Skip
- Cauldron KAPPA: This is the underwater one. It sucks. It’s hard. It’s beautiful. It’s located in the far northwest. You need the diving mask from the "Sea of Sands" main quest to even think about entering. It plays with water levels like an old-school Zelda dungeon.
- Cauldron CHI: Located in the Greenhouse area. It’s falling apart. You have to deal with Clamberjaws, which are arguably the most irritating enemies in the game. But the rewards? You get the Stalker override. Being able to turn a stealth-cat to your side is worth the headache.
- Cauldron GEMINI: You can’t miss this one; the story forces you into it. But don't go in under-leveled. It is a gauntlet. It’s the narrative climax for a reason.
The Stealth Factor
Most people treat these as combat arenas. Try stealth.
Seriously. The level design in a Horizon Forbidden West cauldron usually includes "stealth grass" made of synthetic fibers or high walkways that allow you to bypass entire encounters. You can actually sneak through a large portion of CHI and KAPPA without firing a single arrow until the boss. It changes the atmosphere completely. It feels like Splinter Cell but with more robots.
The lighting is your best friend. In the dark, blue-lit corridors, the machines have specific patrol paths that are much more rigid than in the open world. They are "on the clock." They are workers in a factory. If you watch them, you can see the routine. It’s fascinating and a bit eerie.
Master the Boss Rooms
Every cauldron ends with a shield-dome and a core.
Before you trigger that override, trap the floor. This is Cauldron 101. You have all the time in the world before you touch that center console. Lay down tripwires. Set up acid traps. If you know a Slaughterspine is coming, don't just stand there and wait for it to roar. Turn the floor into a minefield.
A lot of players find the cauldron bosses "bullet spongy." They aren't. You’re just not using the environment. Look for the canisters. Look for the heavy weapons you can shoot off the boss and then pick up. In Cauldron KAPPA, use the water. In MU, use the height.
Moving Toward the End Game
Once you’ve conquered every Horizon Forbidden West cauldron, you basically become the master of the ecosystem. But the game doesn’t tell you that some machine variants—the Apex versions—cannot be overridden. Don't be the person trying to sneak up on an Apex Tremortusk thinking you’re going to ride it into battle. You can’t. They are too "corrupted" by HEPHAESTUS’s malice.
The real value of the cauldrons isn't just the overrides, though. It’s the lore. Read the data points. They describe the "Sovereign Test" and how the AI started viewing humans as a virus. Each cauldron is a chapter in a manifesto written by a machine that just wants to be left alone to build things.
Actionable Next Steps for Your Playthrough
- Check your Level: Do not enter Cauldron KAPPA until you are at least level 35 and have the breathing apparatus. You will regret it.
- Farm the Parts: Before you go to a cauldron, check which machines it unlocks. If it unlocks a Ravager, make sure you have some Ravager parts in your stash so you can instantly craft the override at your base.
- Use the Focus: Spend five minutes just scanning the internal machinery. The "yellow" handholds aren't always obvious in the strobe lights of the factory.
- Respec for Impact: If you’re struggling with a boss, swap your skill points into the "Machine Master" tree. It makes your overridden machines tankier and do more damage.
Cauldrons are the best part of Horizon Forbidden West. They are weird, beautiful, and frustrating. Stop rushing them. Look at the walls. Watch the assembly lines. Appreciate the fact that you’re standing inside a god’s ribcage.
The Forbidden West is a big place, but its secrets are all manufactured underground. Go find the next core and take back control of the wilds.