There’s a big secret waiting for you underground in Elden Ring. Right from the start of the game, you can access a hidden area of the map that’s surprisingly vast and filled with tough enemies — and a bonus boss fight against a strange creature you can easily miss. The Siofr River is one of the coolest early discoveries you can make in Elden Ring, and here I’ll explain how to find it, and how to unlock the optional unique boss fight deep inside this dungeon.
Skip this intro if you want to be surprised. I have to talk about the Siofr River — a massive underground ancient city, with megalithic Greek columns and spectral hunters. The sky is made up of glinting crystals on the ceiling of the cavern. The entire area is incredible, and there are some very handy items for sale by a lost vendor. You’ll also find a weird temple called Hallowhorn Grounds. This is where you’ll be able to activate a bonus boss fight. And it is a very cool one.
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How To Reach The Siofr River Region
Travel east from the Stormgate ruins to find the Mistwood. This foggy forest is guarded by Rune Bears and other powerful creatures. There’s also a Minor Erdtree nearby. To enter the Siofr River area, travel north from the Minor Erdtree into the Mistwood and search for a large structure called the Siofr River Well.
Enter the Siofr River Well structure and ride the lift down. You’ll go straight into the Siofr River — there’s a map near the entrance. This is an entirely new region hidden underground, with its own separate map. There is a vendor here that sells a respec item and a secret boss located at the Hallowhorn Grounds. The large temple is near the ledge, and it marked with eight unlit obelisks.
How To Fight The Ancestor Spirit | Secret Boss
Deep underground, you need to activate 8 obelisk stones. Each stone lights a fire at the Hallowhorn Grounds temple. The stones are tall pillar-like objects with text on them. Finding all 8 isn’t too hard, they’re scattered around the area and aren’t hidden. You’ll need to be able to fight the ancestral hunters to clear the way to each.
After lighting the 8 obelisks, return to the old temple and interact with the dead body to initiate the fight. You’ll teleport into a strange room deep under the water’s surface with a fog door. Step through to encounter the boss.
- Ancestor Spirit Boss Tips:
- The boss is a spectral undead deer with glowing incantation magic and huge antlers. It runs on magical hooves, allowing it to fly, and spews blue fire from its glowing antlers.
- Stay at its flank. If you’re behind it can rapidly kick you with its hind legs.
- From the front it can spew blue fire breath. Try to dodge around it and attack the core.
- You can safely attack it after it lunges at you with its antlers. Dodge straight forward and strike. You can also back away and wait for it to trot in the air toward you, smashing downward after two steps. Dodge straight forward and strike.
After defeating the Ancestor Spirit, you’ll unlock the Ancestral Followers Ash — Ash Spirits you can summon to help you. These are the creatures you’ve been fighting down below. They’re strong helpers, and if you upgrade them, they can be even better.
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