Hey, I’m Yuzukaki. 👋
If you play Survival, you know the pain: grinding for drops and experience points (XP) can get really old, really fast.
The good news is, once you understand the basic mechanics, you can build a simple structure that quietly farms both items and XP for you.
That structure is a mob farm built high in the sky — in Japanese we often call it a “sky trap tower,” but in English, mob farm is the standard term.
And this particular design is fully no redstone: no redstone dust, no observers, no repeaters.
In this guide, I’ll walk you through the build step by step so that even if this is your very first mob farm, you can still finish it without getting lost.
Again: no redstone circuitry required — as long as you have water buckets, some solid blocks, hoppers, and trapdoors, this farm will work.
Take your time and follow along to the end, okay?
This design is aimed at beginners who have just finished building their first base.
On purpose, I’m not pushing for crazy “best possible” efficiency or complex optimizations.
This farm works in Minecraft Java Edition only — behavior is different in Bedrock Edition.
This article was published as an English translation of a Japanese blog post.
Table of Contents
1. What Is a High-Altitude Mob Farm?
2. Materials You Need Before Building
3. Build the AFK Platform & Elevator
4. Build the Kill Chamber (Processing Layer)
5. Build the Spawning Platforms (Spawning Layers)
6. Troubleshooting When It Won’t Work
7. Wrap-Up
Click any heading in the table of contents to jump to that section.
1. What Is a High-Altitude Mob Farm?
A high-altitude mob farm is a build that sits high above your world and concentrates hostile mob spawns into one place so you can farm them efficiently and safely.
As you can see in the screenshot, the whole farm floats far above my base.
With this one structure you can mainly farm:
- Drops from hostile mobs
- Gunpowder
- Bones
- Arrows
- Bows
- Rotten flesh
- Armor (leather, iron, gold, diamond, etc.)
- Experience points (XP)
- You can also set up an enchanting area nearby to make it extra convenient
Use it as an XP farm and enchanting becomes way easier; use it as a drop farm and you’ll get a steady supply of Survival essentials without grinding caves all day.
I really recommend building at least one of these near your main base to make your Survival life much smoother.
To be fair, there are other specialized farms (raid farms, Enderman farms, etc.) that beat this design in raw efficiency.
But as a first mob farm for beginners, the bar to build it is much lower, and it’s still very useful in early–mid game.
2. Materials You Need Before Building
Alright, let’s get ready to build our mob farm.
Here’s what you should gather beforehand:
- Solid blocks (from a few to several dozen stacks of blocks)
- Any full block that blocks light is fine: stone, cobblestone, iron blocks, etc.
- Trapdoors (about 1 stack per spawning layer)
- Used to create “fake floors” so mobs accidentally walk into the water channels
- Slabs
- Used for spider-proofing, placed every 2 blocks
- Glass
- Used to enclose the drop shaft and make the build easier to see while you work
- Hoppers & chests
- For automatic item collection
- Water buckets, soul sand, kelp
- For building the bubble column elevator
- Torches (or any other light source blocks)
- Used to spawn-proof the roof and the ground below
- Ladders
- For a manual up/down path if you want one alongside the water elevator
You’re going to need a lot of blocks, but as long as they’re light-blocking full blocks, they’ll work.
If you’re still early in Survival, a big chest of cobblestone is totally fine. 👌
If you care about how it looks from your base, use “polished” variants or other nicer-looking blocks to dress it up later.
In my world, I had already built an iron farm, so I went overboard and made the whole thing out of iron blocks…
But seriously, cobblestone, dirt, whatever — as long as the spawning floors are completely dark, the farm will work.
Note: Make sure the spawning rooms have no block light (light level 0) and are fully sealed from skylight with opaque blocks.
3. Build the AFK Platform & Elevator
From this section onward, we’ll actually build the mob farm together.
3-1. Pick a Good Location
We build it way up in the sky so that hostile mobs on the ground stop competing with your farm and most spawns get funneled into the dark platforms you built.
Because mobs stop spawning (and despawn) once they’re far enough from you, you want a place where the area below the farm isn’t full of tall terrain inside your 128-block radius — avoid mountain ranges and build over flatter land if you can.
3-2. Pillar Up and Make a Platform
Once you’ve chosen the spot, pillar up with dirt or any spare blocks all the way into the sky.
For height, a safe rule is: build your farm so the ground is more than 128 blocks away from where you’ll be waiting/AFK.
In a lot of normal terrain, building around Y=200 works out fine, but what matters is the distance, not the exact Y-level.
From my own experience:
The first time, I thought “eh, the height doesn’t matter that much” and built it too low.
Result: almost no mobs spawning → ended up rebuilding the whole thing…
So yeah, don’t ignore the height requirement.
Once you reach your target height, build a small platform — this will be the foundation for your kill chamber (processing layer).
3-3. Build a Water Elevator to Travel Up and Down
With the platform in place, next we’ll build a water elevator so you can easily travel between the ground and the farm.
We’ll do it in these steps:
① Build a 1×1 shaft with four walls
Build four vertical walls (a 1×1 column) to surround the water source.
Use whatever block you like, but if the elevator is near your base, glass looks really nice.
② Place water at the top
After you’ve finished the four walls, go to the top and place a water source in the center of the shaft.
The water will flow all the way down to the ground.
③ Turn the whole shaft into water source blocks with kelp
In Java Edition, just placing flowing water isn’t enough to make a bubble elevator.
So from the bottom, plant kelp all the way up to the top, turning every block of flowing water into a source block.
Story time:
I jumped into the water column with kelp in hand, planning to plant it all the way up…
And I almost drowned before I reached the top. 👼
If you have a Water Breathing potion or a helmet with Respiration, it’s much safer.
④ Replace the bottom block with soul sand
Break the bottom block under the water and place soul sand there.
This makes the entire column produce bubbles, and when you stand in it, it will push you upward as a bubble elevator.
If you see bubbles rising all the way up, you’re good to go.
That’s your path between the ground and the sky farm completed.
From here, we’ll start building the actual mob farm up in the sky.
4. Build the Kill Chamber (Processing Layer)
In this section, we’ll build the kill chamber where mobs fall and you finish them off.
4-1. Place Hoppers on the Floor to Collect Drops
Using the screenshot as a reference, build a hopper floor:
- ① Inset a 4×4 floor of hoppers into your platform
- ② In the center of that, add a 2×2 cluster of hoppers
- ③ You can connect these hoppers to a chest so anything you pick up by accident gets sent away too
I recommend routing the hoppers down to a storage area on the ground — having all your drops end up in a nice sorting system later feels great.
4-2. Build the Kill Window
After the floor is in place, build the window where you’ll hit the mobs.
Based on the screenshot:
- Build up two full blocks high for the walls
- Then make an arch-shaped opening using slabs so that only the mobs’ feet are visible
- To make it easier to hit them, place fences along the bottom of the window
This lets you damage mobs while keeping yourself safe.
4-3. Wrap the Kill Chamber in Glass
To keep everything contained, make sure to fully enclose the kill chamber in glass walls.
Double-check for any gaps — even a small hole can cause trouble later (yes, I learned that the hard way).
From experience:
After finishing the farm I thought, “Let’s add some automation!” and temporarily removed part of the glass.
A creeper dropped down, got a clear path to me, and then… BOOM.
My kill chamber was completely destroyed.
Once it’s finished, avoid tearing down the walls unless you really have to.
4-4. Extend the Glass Walls Up to the Spawning Floors
Next, extend the glass walls straight up.
How tall you make this drop depends on how you plan to use the farm:
- If you want an XP farm → aim for a 22-block drop (most common hostile mobs survive with about half a heart, so you can finish them in one hit)
- If you only care about drops → aim for at least a 24-block drop (most common hostile mobs die from fall damage; witches can take closer to a 30-block drop)
One important rule: mobs won’t naturally spawn if you’re within 24 blocks (spherical distance) of the spawning floor.
So whatever heights you choose, make sure your “waiting/AFK” spot isn’t too close to the spawning platforms.
Note:
- For an XP grinder, ~22 blocks usually leaves most common mobs at one-hit HP, but it can vary slightly.
- For a drop-only grinder, 24+ blocks kills most common mobs; witches often need ~30.
4-5. Cap the Glass Shaft with Two Layers of Solid Blocks
Once the glass shaft is up to the correct height, add two more layers of solid, non-transparent blocks (like stone) on top.
This is to keep any light from reaching the spawning platforms we’ll build next.
From experience:
I originally made the whole shaft out of glass, which let light in and killed the spawn rates.
So: always finish the top two layers with non-transparent full blocks.
With that, the kill chamber and drop shaft are done.
Now we move on to the main part of the build: the spawning platforms.
5. Build the Spawning Platforms
In this section we’ll build the spawning layers where mobs actually appear.
I’ll go step by step, so take it slowly and make sure each part matches the screenshots.
5-1. Build the Water Channels
This mob farm uses a water-stream design with no redstone.
The idea is simple: mobs spawn on dark platforms, walk into water channels, get pushed to the center, and fall into the kill chamber.
Let’s start with the water channels:
From the 2×2 hole in the center (the drop shaft), build 8 blocks of floor outwards in all four directions.
Leave the center 2×2 open.
Once the floor is done, build the channel walls:
Surround each channel with 2-block-tall walls, making sure there are no gaps for water to leak out.
Then, place water sources at the outer ends of each channel so that the water flows toward the center and stops right before the 2×2 hole.
If you’re building in a cold biome while the top is still open, your water sources can freeze.
If that happens, just break the ice and replace the water sources.
That’s the water channels finished!
5-2. Build the First Spawning Floor
Now that the channels are done, let’s create the first spawning platform.
From the top of the 2-block-tall channel walls, connect the four corners so that, viewed from above, everything forms a big square.
Next, completely fill in the square with solid blocks so there are no gaps.
Once that’s done, your first spawning floor should be complete.
To encourage mobs to fall into the channels, place trapdoors over the water like in the screenshot.
Mobs see trapdoors as solid blocks and will happily walk “off” them into the water.
After placing the trapdoors, right-click them so they’re in the open position, exposing the water below — don’t forget this part.
To reduce spider spawns, place bottom slabs every 2 blocks across the floor.
Spiders need a 3×3 open area to spawn, so breaking up the floor like this helps a lot.
From experience:
I once forgot to place the slabs, and spiders started spawning and clogging the farm.
Unless you specifically want spiders, don’t skip this step.
If your floor looks like the screenshot above, your first spawning layer is good to go.
Once you’ve checked that, we can stack more layers on top.
5-3. Build the Second and Higher Spawning Floors
From the second layer onward, you can simply copy the first floor’s design exactly.
The only thing to pay attention to is the ceiling height between layers.
Let’s build the next one together.
To prevent Endermen from spawning and messing with your blocks, make sure the ceiling height is exactly 2 blocks.
As in the screenshot:
- Build walls so the interior height is 2 blocks
- Then cut 2-block-deep openings down to the water channels, just like on the first floor
Just like the first layer, fill in the entire floor with solid blocks.
Again, place trapdoors over the holes leading to the channels and open them so mobs walk in and fall down.
Repeat the same spider-proofing: place bottom slabs every 2 blocks across the floor.
If your second layer looks like this, you’ve successfully copied the first floor’s design.
From the second floor upward, the pattern is always the same:
Make 2-block-high walls and ceiling → place trapdoors over the channel openings → place slabs every 2 blocks for spider-proofing.
If you want more layers, just repeat this pattern as many times as you like.
In terms of efficiency vs. effort, around 3 layers is a nice sweet spot.
5-4. Close Off the Roof
Once you’ve built as many spawning floors as you want, it’s time to seal the roof so the entire interior is pitch-dark.
Once the roof is completely sealed with blocks, don’t forget to spawn-proof the top surface with torches.
Once the roof is spawn-proofed, the mob farm is structurally complete!
If you’ve made it this far, nice work — it’s a long build, so seriously, good job hanging in there.
5-5. How to Use the Mob Farm Once It’s Finished
After everything is built, use the farm like this:
A couple practical tips:
- Make sure you’re at least 24 blocks away from the spawning floors while you’re waiting, or mobs won’t spawn.
- Once you’ve let a bunch of mobs fall into the chamber, step up to the window and finish them off for XP.
Then just repeat those steps.
That’s all — you’ll steadily get both XP and mob drops.
6. Troubleshooting When It Won’t Work
If you feel like:
“Mobs barely spawn…”
“Something feels off, the farm is weak…”
👉 Use this checklist to track down the problem:
- [ ] Is your waiting/AFK spot far enough from the ground (and far enough from the spawning floors) to avoid competing spawns and the 24-block no-spawn radius?
- [ ] Did you remember to place all the slabs for spider-proofing?
- [ ] Is there any light leaking into the spawning floors?
- [ ] Is the drop height set correctly for the way you want to use the farm (XP-friendly vs. auto-kill)?
- [ ] Are the glass walls around the kill chamber fully closed, with no gaps?
7. Wrap-Up
That’s the whole build!
I tried to lay it out so that even players who struggle with complex contraptions can follow a simple set of steps and end up with a working farm.
This mob farm design:
- Uses no redstone at all — everything is done with water streams
- Is relatively cheap but still gives you a ton of XP and mob drops once it’s running
To recap the important points:
- Build high enough that the ground is more than 128 blocks away from where you’ll be waiting/AFK, so you don’t compete with surface and cave spawns
- Stay at least 24 blocks away from the spawning floors while waiting, or mobs won’t spawn
- Adjust the drop height depending on whether you want an XP farm (mobs survive) or a pure drop farm (mobs die)
- Follow the spawning-floor pattern carefully and remember the spider-proofing slabs
If you do all three, your mob farm should run just fine.
Note: This farm relies on Java Edition mechanics.
Behavior and spawn rules are different in Bedrock Edition, so please keep that in mind.
If you’re up for it, I’d really like you to try building this mob farm in your own world.
Once your XP and drops are on autopilot, enchanting and building other contraptions becomes way less of a grind.
Alright, that’s it for today.
Thanks a lot for reading all the way to the end. 🙌
Update History
- 2026/02/16 Initial release
