Nether Fortress

From Minecraft Wiki
(Redirected from Fortress)
Jump to: navigation, search
Nether Fortress
Nether Fortress.png

Nether[until JE 1.16]
Nether Wastes[upcoming: JE 1.16], Soul Sand Valley[upcoming: JE 1.16]
Any biomes in the Nether[BE only]

Consists of

See Structure

Nether fortresses, also known as simply fortresses, are large, bridge-like structures found in the Nether.


Segments of a Nether fortress that are fully enclosed.

Nether fortresses tend to cluster together in strips that run along the Z-axis (north and south).[verify] Players who travel along the X-axis (east or west) have the best chances of finding one; those who travel north or south may travel for hundreds or thousands of blocks before discovering a nether fortress. Upon finding a nether fortress, it is best to travel in the North/South directions to find more nether fortresses along the same stripe.

Nether fortresses may be generated in inconvenient places, where half of or even the majority of the fortress is buried in netherrack. In such a case, the interior is not filled with netherrack; all hallways and passages are clear except for open walkways and bridges. It is rare but possible for glowstone to generate inside the fortress pathways.


The general pattern of the walkways.
A lava well found inside a Nether fortress.

Nether fortresses are very large bridge-like complexes, composed mainly of nether bricks, that are supported by massive pillars that tower high above the lava oceans. A fortress has two areas, an exterior area of open bridges and an interior area of enclosed corridors. Both the bridges and corridors can end in a "broken" structure or may simply end without elaboration. Fortresses can tunnel through netherrack, giving the "exterior" areas an appearance of tunnels with nether brick floor and netherrack walls and ceilings. At broken sections the terrain is not cleared, which may create a tunnel that leads straight into a wall of netherrack.

The exterior consists of:

  • Straight bridges.
  • Up to 5 plain four-way crossings.
  • Up to 4 four-way crossings with arches made of nether brick and nether brick fence.
  • Up to 4 small rooms with a single entrance, and full-block "stairs" leading to the roof, which may have a single path leading out.
  • Up to 2 blaze spawner platforms: structures consisting of three full-block "stairs" leading to a small platform fenced with nether brick fence, with a blaze spawner in the center.
Stairs in a nether fortress, with nether wart growing next to them.

The interior of the structures have 1×2 windows with nether brick fences as the windowpanes. The fences also form gate-like structures at the entrances of some rooms and corridors. Rooms include:

  • The lava well room, which is the connection between the interior and exterior areas.
  • Straight corridors.
  • Up to 5 four-way crossings.
  • Up to 20 corridor turns (10 right-turns and 10 left-turns), each with a 13 chance of having a loot chest in the corner.
  • Up to 3 stairways (made from actual stair blocks) leading downwards.
  • Up to 2 three-way intersections with a small exterior balcony.
  • Up to 2 stairways leading up to an open landing, which have patches of soul sand and nether wart at the base of the stairs, a corridor leading away from the upper landing, and a corridor behind the stairs. If the room is generated embedded in netherrack, only one block above the landing is cleared.


Nether Bricks
Nether Brick Fence
Nether Brick Stairs
Soul Sand
Nether Wart
Blaze Spawner


A blaze spawner generated into the side of some netherrack.

Fortresses use a list of possible mobs to spawn that is separate from the rest of the Nether. Fortresses spawn magma cubes at a much higher rate, and also spawn two exclusive mobs not found anywhere else: blazes and wither skeletons. Normal skeletons and zombie pigmen can also appear. Endermen or ghasts do not spawn in fortresses.

The spawning algorithm has two checks:

  1. It checks if the spawn coordinates are within the "bounding box" of a single piece (e.g. corridor or walkway) of the fortress. In this case the block type of the ground does not matter.
  2. It checks if the spawn coordinates are within the "bounding box" of the entire fortress and whether the ground consists of nether bricks.

If either check passes, it uses the special mob list for fortresses rather than the general list for the Nether when choosing the mob to spawn. The actual mob spawning proceeds as normal for the mob chosen from this list.


A chest that generated in a fortress

Fortresses generate nether fortress loot with chests in the indoor sections placed at some corridor turns. In Java Edition, each nether fortress chest contains 2–4 item stacks, with the following distribution:

Stack Size Weight # Items Chance # Chests
Gold Ingot 1–315731.23349.0%2.0
Saddle 110730.41135.3%2.8
Golden Horse Armor 18730.32929.1%3.4
Nether Wart 3–75731.02719.0%5.3
Iron Ingot 1–55730.61619.0%5.3
Diamond 1–35730.41119.0%5.3
Flint and Steel 15730.20519.0%5.3
Iron Horse Armor 15730.20519.0%5.3
Golden Sword 15730.20519.0%5.3
Golden Chestplate 15730.20519.0%5.3
Diamond Horse Armor 13730.12311.8%8.5
Obsidian 2–42730.2478.0%12.5


Icon Advancement In-game description Parent Actual requirements (if different) Namespaced ID


A Terrible FortressBreak your way into a Nether FortressNetherEnter a Nether fortress.nether/find_fortress



Java Edition
1.0.0September 16, 2011Jeb tweets a teaser screenshot of changes to the Nether terrain generation, including fortresses.
September 19, 2011Jeb releases a second teaser screenshot, showcasing the structure of the upcoming fortresses.
September 21, 2011Jeb mentions that he is finished with most of the new Nether features, including two new mobs, one of which is a "retexturing attempt".
Beta 1.9 PrereleaseAdded fortresses.
1.4.212w36aWither skeletons and skeletons now naturally spawn in fortresses.
Other mobs also found in fortresses spawn less often due to that addition. Zombie pigmen became remarkably more uncommon though due to their weight being halved.
1.6.113w18aChests now generate.
1.814w27aFortresses are now affected by the "Generated structures" option.
14w30aAdded possibility of obsidian in chests.
1.915w43aReduced loot in chests from 2–5 stacks to 2–4.
Upcoming Java Edition
1.1620w06aFortresses can now spawn in the Soul Sand Valley biome.
Pocket Edition Alpha
0.12.1build 1Added fortresses.
0.15.0build 1Horse Armor can be found in chest loot.
Legacy Console Edition
TU7CU11.0Patch 1Added fortresses.
TU9Changed fortresses to make nether wart rooms more likely.
TU19CU71.12Chests now generate.
New Nintendo 3DS Edition
0.1.0Added fortresses.


Issues relating to "Nether Fortress" are maintained on the bug tracker. Report issues there.


  • In extremely rare cases, a fortress might not generate any indoor rooms except one single lava room.
  • Sometimes, two or more fortresses can generate very close or even within each other, ultimately creating an even larger cumulative fortress.
  • Under the lava well, there is an opening out of the fortress, with a single block of nether bricks from which the lava spreads out.
  • With a chance of less than 1% of this happening, a nether fortress can be completely submerged in lava, killing all mobs that generated inside it.[verify]