Soul Fortress Remains is the Legendary Monsters structure for the Nether, a squat 
Blackstone ruin laid over 
Soul Soil. A Withered Abomination is asleep in a cage at the middle of it, and the loot behind that boss is the reason to come.
The ruin itself is free to walk into, there’s no key and no locked gate anywhere in it. 
Chests are tucked into the corners, two 
Wither Skeleton spawners sit under the towers, and the Abomination will stay asleep until you step within 15 blocks of it. Beating it gets you the 
Withered Horns and 
Withered Bones needed to craft the 
Withered Scythe and the 
Withered Ribcage.
Finding the Structure
It only generates in the Nether, and only in two vanilla biomes. If you’re running Biomes O’ Plenty it will show up in Withered Abyss and Visceral Heap as well, and those two are easy to walk past, so keep an eye out in them.
There’s one roughly every 27 chunks, so they’re spread a lot thinner than Nether Fortresses are. Wandering for one isn’t really the plan, instead you’ll want an 
Eye Of Soul. Four 
Soul Sand around an 
Ender Pearl makes one, and throwing it sends it off toward the nearest Soul Fortress Remains within 100 chunks.
It flies as an ordinary 
Eye of Ender does, so it survives most throws and drops back where it lands. If no fortress sits inside the search range, the eye isn’t used at all. Every structure in the mod has an eye like this, covered in Boss Summoning: Eyes & the 
Teleport Machine. With cheats on, the locate command skips the search entirely.
Either way, once you’re there the ruins are low and open, so the Withered Abomination in the middle is usually the first thing you’ll see. It stays asleep until you’re close, which gives you time to look around the edges.
Layout
The ruin is wide and low, so most of it reads as a floor plan rather than a building. 
Polished Blackstone, Blackstone and 
Smooth Basalt make up nearly all of it, sitting on a pad of 
Netherrack and Soul Soil, with 
Soul Lanterns on top of the pillars and patches of Soul Fire across the floor.
A raised platform sits in the middle with a Block of Gold at its heart, and the Withered Abomination sleeps on top of that. Around the platform is a cage of 
Nether Brick Fence and 
Blackstone Wall under a slab lattice. There’s no door and no 
Lever, as the Abomination smashes the walls out itself when it stands up.
Two of the four corners rise into short towers. At the base of each one a Wither Skeleton spawner sits in the floor behind a pair of 
Warped Doors, and a Chest sits on the tower roof above it. The other two corners hold a Chest each at ground level, out in the open with nothing guarding them at all.
Mobs
There are only a few things living in the ruins, and most of what you fight comes out of a spawner rather than being placed. The table below is everything you’ll meet inside the walls, boss included.
| Enemy | Where it comes from | Numbers |
|---|---|---|
| Withered Abomination | Asleep on the center platform, placed by the structure itself | 190 HP, 12 armor, 15 attack damage, 3 blocks wide |
| Wither Skeleton | Two spawners, one at the foot of each tower | 4 per spawn, 6 alive at once, every 10 to 40 seconds |
| Nether biome spawns | Ordinary biome spawning around and inside the ruin | Nether regulars, plus a Skeletosaurus if the ruin landed in Soul Sand Valley |
The Withered Abomination is the only mod mob the structure actually places, and it arrives asleep. It has its own article with the full fight in it, so the short version is that it’s a melee boss with 190 HP that won’t take a scratch until it wakes up. It counts as Undead, so Smite is doing real work where Sharpness is not.
The two spawners are what usually goes wrong. Each one runs whenever a player is inside 16 blocks, throwing out Wither Skeletons a few at a time up to 6 alive. Both sit close enough to the middle that the boss fight keeps them running, so it comes with skeletons whether you want them or not.
Mobs won’t open the Warped Doors, but the spawner scatters its skeletons up to 4 blocks out, so some land outside the doorway anyway. Mining a spawner out is the only thing that stops it for good, as covering the block does nothing about those.
Beyond that it’s whatever the biome hands you. Nothing else in the ruin is scripted, so a 
Ghast drifting over the wall or a pack of 
Piglins following you in is just the Nether doing its usual thing. The one to watch for is a Skeletosaurus, which the mod adds to Soul Sand Valley spawns and which brings 150 HP and 13 attack damage of its own.
Loot
The two ground-level Chests and one of the tower roofs run the vanilla Nether Fortress table. They roll 2 to 4 times each, so a full clear of those is a decent pile of 
Gold Ingots and horse gear more than anything else.
Corner and Tower Chests
Gold Ingot 
Saddle 
Golden Horse Armor 
Diamond 
Iron Ingot 
Golden Sword 
Golden Chestplate 
Flint and Steel 
Nether Wart 
Iron Horse Armor 
Smithing Template 
Diamond Horse Armor 
Obsidian The other tower roof is the one worth climbing for, as it runs the Bastion Treasure table instead. It hands over a Netherite Upgrade Smithing Template every single time, plus several more rolls of Netherite, Diamond and ore loot. It sits on the roof of one of the two towers and you can’t tell which from the ground, so check both.
The Bastion Treasure Chest
Smithing Template 
Netherite Ingot 
Ancient Debris 
Diamond Sword 
Diamond Chestplate 
Diamond Helmet 
Diamond Leggings 
Diamond Boots 
Gilded Blackstone 
Nether Quartz 
Block of Gold 
Block of Iron 
Crying Obsidian 
Spectral Arrow Gold Ingot Iron Ingot 
Magma Cream 
Smithing Template 
Netherite Scrap Diamond 
Enchanted Golden Apple So a full clear gets you some fortress loot, one Bastion treasure Chest and whatever the Wither Skeletons drop, on top of the boss parts. It isn’t a rich structure, though, and the Withered Abomination is what you’re there for.
What the Horns and Bones Make
The Abomination doesn’t wait until it dies to pay out. It sheds a Withered Horn the moment it drops below half health and a second one below a quarter, and both land on the floor mid-fight, so pick them up before something knocks you off the platform. Dying adds 2 Withered Bones and 100 experience on top.
Withered Abomination Drops
That’s 2 Horns and 2 Bones per kill, exactly enough for one Withered Scythe or one Withered Ribcage but never both, so you’ll need a second fortress for the pair. The Scythe also wants a Block of Gold, and there’s one under the Abomination’s feet in the middle of the platform, so mine it once the fight is over.
The Withered Scythe is a slow, heavy weapon, and holding right-click charges you forward through anything in the way for 10 damage and Wither II. The Withered Ribcage is a chestplate that strips the Wither effect off you while it’s worn and sometimes puts it back onto whatever hit you. Against a boss that applies Wither with nearly every swing, that makes the Ribcage the stronger first pick.
The Boss
Nothing summons it, as the Withered Abomination is already in the structure, asleep. It wakes when a player comes within 15 blocks, and that radius covers the whole floor of the ruin, so both ground Chests and both spawners sit inside it. Only the two tower roofs are far enough out to loot in peace.
A sleeping Abomination ignores every normal damage source, so 
Arrows, 
TNT, Lava and Splash Potions all do nothing to it before it stands up. There’s no safe opener and no chip damage to bank, you just have to walk in and wake it.
Standing up is also what opens the cage. The wake animation breaks the blocks around it, which takes out most of the walls and leaves it free to come at you, so the pen you found it in is gone before the first swing lands.
Once it’s awake it fights entirely up close, with wide arm sweeps, a slam that sends shockwaves across the floor and a ground smash. Every hit puts Wither II on you for 2 seconds, and most of them knock you back and up, which is fine with room to move but turns into a wall bounce against what’s left of the cage.
A 
Shield stops the damage, the Wither and the knock-up all at once, but each blocked hit disables it for somewhere between 3 and 7 seconds depending on what landed, so you can’t just turtle through the fight. It gets more mobile as it cracks, gaining a block-breaking dash below half health. The full attack list is on the Withered Abomination page.
Exploration & Strategy
A trip out here is a Nether trip first and a boss fight second, so the list below covers both. The Milk is for the Wither the boss gives you, and the Fire Resistance is for everything else.
The boss won’t wake on its own, but the 15 block radius is wide enough that almost nothing on the floor is safe to touch first. That decides the order, so the towers come before anything else and the fight comes before the clean-up.
Take the tower roofs first
The only spots outside the radius
Get up both towers and empty the Chests on top of them, since one of those roofs is holding the Bastion Treasure Chest with its guaranteed Netherite Upgrade Smithing Template. The roofs sit far enough from the center that neither one wakes the boss, so this is the whole of what you can do in peace.
Set a respawn point
Outside the ruin
Charge a 
Respawn Anchor somewhere outside the walls. The Abomination hits hard enough that a first attempt might not go your way, and a respawn on the doorstep beats a run back from the Overworld through a portal you’ll have forgotten the coordinates of.
Wake it and back off
Fight it in the open
Wake it from the edge of the courtyard, then back off as it gets up. It breaks its own cage open, so don’t climb in after it. A pen leaves you nowhere to stand against its sweeps, whereas the open courtyard lets you walk out and heal, with room behind you instead of Blackstone. Expect Wither Skeletons the whole time, as both spawners keep running.
Clear the floor afterward
Ground Chests, spawners, Gold Block
With the boss down, take the two ground corners, mine both spawners out of the floor so the ruin stops producing skeletons, and pull the Block of Gold from under where it was sleeping. None of that is worth doing first, because every one of those spots is inside the radius that starts the fight.
Leave a few things at home, as they don’t work on it. Fire, Lava, fall damage and Wither damage are all shrugged off completely, and thrown Potions of any kind do nothing to it, so a 
Splash Potion of Harming is a wasted slot. Knockback is out too, as its resistance is maxed, so Punch Bows and Knockback swords won’t buy you any room.
FAQ
It’s a Nether-only structure, and it sits on the surface in Soul Sand Valley and Nether Wastes. With Biomes O’ Plenty installed it will also generate in Withered Abyss and Visceral Heap. There’s about one every 27 chunks, which makes it noticeably rarer than a Nether Fortress, so you might cross several biomes without seeing one.
Craft an Eye Of Soul from 4 Soul Sand around an Ender Pearl, then throw it and follow it. It searches out to 100 chunks and flies at the nearest Soul Fortress Remains, and like a vanilla Eye of Ender it usually survives and drops back for you to pick up, so one or two will see you there. Failing that, the locate command will hand you coordinates directly.
A sleeping Abomination refuses every ordinary damage source, so Arrows, Lava, TNT and Potions are all ignored until it stands up. It also can’t be given status effects in that state, which rules out lingering clouds as well. It wakes when a player gets within 15 blocks of it, so the only way in is to walk up and start the fight properly.
One kill gives you 2 Withered Horns and 2 Withered Bones, and both the Withered Scythe and the Withered Ribcage want 2 of each, so a single fortress only covers one of them. Looting doesn’t change that either, as the Horns are dropped at fixed health thresholds and the Bones are a flat count. A second fortress is the only way to end up with the pair.
