Stronghold

A stronghold is a structure that occurs naturally underground in the Overworld, and is the only place where an end portal can be found. Strongholds can be located by using an eye of ender.
== Generation ==
Strongholds generate at any Y level, mostly underground, and prefer to generate in biomes above sea level, but generate underwater if necessary. Strongholds may generate at bedrock level, cutting the bedrock.
Most parts of the stronghold can be overwritten by caves, ocean monuments, ancient cities, mineshafts, fossils, amethyst geodes, and monster rooms; but it is rare for the end portal to be replaced, which would force a player to find one of the other strongholds, as a portal can be activated only with all 12 end portal frames present. Canyons do not overwrite strongholds; rather, a stronghold can occasionally be found exposed by a canyon.
=== Bedrock Edition ===
, strongholds generate randomly throughout the world and they are at least 160 blocks away from the world origin. There is no limit to the number of strongholds that can generate, unlike in Java Edition. There are 3 extra strongholds at least 453 blocks away from the world origin, which tend to be close to the origin, and are guaranteed to generate below a village.
Because Bedrock Edition begins stronghold generation at a spiraling staircase, it is rare to find no portal room in the stronghold.
=== Java Edition ===
, all strongholds are located at random coordinates within rings in all biomes, where each ring is a certain radius from the center of the world (X=0, Z=0). For a given ring, the strongholds are generated at roughly equal angles from the center point of the world (for instance, each stronghold in a ring of 3 is in the region of 120 degrees from the others, measured from the origin). The game does not generate a stronghold partially above-ground, any portion above the sea level is replaced with air, leaving a cutaway. If a stronghold generates in an ocean, which occurs rarely, it typically generates with terrain covered above it.
There are eight rings, containing 128 strongholds in total:
# The first ring has 3 strongholds within 1,280-2,816 blocks of the origin.
# The second ring has 6 strongholds within 4,352-5,888 blocks of the origin.
# The third ring has 10 strongholds within 7,424-8,960 blocks of the origin.
# The fourth ring has 15 strongholds within 10,496-12,032 blocks of the origin.
# The fifth ring has 21 strongholds within 13,568-15,104 blocks of the origin.
# The sixth ring has 28 strongholds within 16,640-18,176 blocks of the origin.
# The seventh ring has 36 strongholds within 19,712-21,248 blocks of the origin.
# The eighth and outermost ring has 9 strongholds within 22,784-24,320 blocks of the origin.
== Structure ==
Strongholds vary in size. They contain several doors and rooms made mostly of stone bricks (45%), mossy stone bricks (30%), cracked stone bricks (20%) and infested stone bricks (5%). Infested cracked stone bricks and infested mossy stone bricks do not generate, unless silverfish enter these blocks. Strongholds are lit by enough torches to provide visibility in most areas, though not enough to suppress mob spawns. Stairs that generate within these structures include stone brick and cobblestone stairs, but not their mossy variants. 
In generated chest corridors and storerooms, dispersed chests containing a variety of loot can be found.
=== Rooms ===
Strongholds feature various types of main rooms. Each room has an entrance, which is either a plain 3×3 opening, a wall with a wooden door, a wall with an iron door (with a stone button on each side), or a 3×3 opening with a gate of iron bars along the top and sides. Rooms may have exits to other room pieces or dead-end "exits" into stone. Additional "passages" between rooms may exist if their generation overlaps or if the stronghold intersects a cave, mineshaft, or other structure. Sometimes, doors can be sealed off by stone bricks in 5-way crossings, resulting in "secret doors".https://www.youtube.com/watch?v=vztJNmUdyBY&t=37s
Stronghold generation begins with a spiral staircase room with a 5-way crossing at the bottom, with additional rooms being randomly generated from the exits of previous rooms up to a maximum distance of 50 rooms and 112 blocks horizontally. If a portal room is not generated, the generation is redone. 
The wooden and iron doors always face the direction the stronghold generates towards, meaning a door flush with the wall always leads away from the starting staircase, and a door indented into the wall leads towards the starting staircase. 
*End portal room: Contains an end portal and a silverfish monster spawner. There are two pools of 3 lava sources in the front sides of the room and a bigger lava pool of 9 below the end portal, and 16 windows of 2 iron bars in the room, with the entrance, always being a gate of iron bars. In most cases, this room cannot be overwritten by other structures generated around it. Only one generates per stronghold, and it is never within 5 rooms of the starting staircase, although it is less likely to generate farther away from the starting staircase. Each portal frame has a 10% chance to generate containing an eye; the average number of portal frames found prefilled is 1.2. The chance of the portal being completely pre-filled is one in a trillion (1:1,000,000,000,000 or 10-12).
**, all seeds for 1.16 that have a pre-activated end portal in the first ring have been found.https://github.com/hube12/SSGOutput/releases/tag/1.1
** , some strongholds do not generate with end portal rooms.
*Library (see below): 0–2 libraries per stronghold, and never within 4 rooms of the starting staircase.
*Large room: A room with three exits (four counting the entrance). The center of the room may have various decorations. 0–6 rooms per stronghold.
** Empty room: Has no decoration.
** Stone Pillar room: Has a stone brick and stone slab pillar with torches on it.
** Fountain room: Contains a fountain in the center, which consists of a stone brick ring and pillar with a water source block on top of the pillar.
** Storeroom: A dual-level room, each 2 blocks high, with a cobblestone center structure joining the two. A lone torch is housed within the structure. A ladder runs up the sidewall for access to the second floor, which is a chamber made of oak planks containing a loot chest.
* Five-way crossing: Has up to five exits (six counting the entrance): one across from the entrance down a short stairway made of smooth stone slabs and stone brick blocks, one each to the left and right of the entrance, one on the left side of the upper level reached by a short stairway made of smooth stone slabs and stone brick blocks, and one on the right side of the upper level across a bridge of smooth stone slabs and double smooth stone slabs over the downward stair. A single torch is on the side of the bridge. , it usually has 1–4 entrances sealed. There is always one crossing in every stronghold as part of the starting point, while an extra 0-4 crossings may also generate.
*Empty prison cells: A corridor with one wall partially made of iron bars and with two iron doors (in an "open" position, with no buttons). Beyond each iron door are cells with an iron bar wall between them. An exit is opposite the entrance. 0–5 rooms per stronghold. , no iron doors are generated.
*Spiral staircase: A 3×3 spiral stair made of stone bricks and smooth stone slabs, leading down, with an exit at the bottom. Like 5-way crossings, there is always one flight per stronghold as part of the starting point, while an additional 0–5 flights may also generate.
* Straight staircase: A 3 block wide staircase of cobblestone stairs leading downward, with an exit at the bottom of the stairs. There is also an empty alcove under the stairs. 0–5 flights per stronghold.
* Corridor: A bare corridor with up to 3 exits: one straight ahead, and optional exits to the left and right.
* Chest corridor: A corridor with a small altar made of stone brick slabs, with a loot chest on the altar. An exit is on the opposite side of the entrance. 0–4 corridors per stronghold.
* Corridor turn: A bare corridor with one exit, left or right. May resemble a small room if both the entrance and the next room's entrance have doors.
* Dead-end corridor: A bare corridor with no exits, although it is likely to intersect other rooms. This room type never has a door or gate at the entrance.
=== Libraries ===
 
Libraries occur in two sizes: small single-level libraries and larger duplex libraries. All libraries contain bookshelves, oak planks, and one (single level) or two (duplex) chests, with cobwebs dispersed randomly.
Small libraries usually generate when the second level of the library is blocked by another part of the stronghold. If there are no obstructions, then large libraries usually generate.
Large libraries contain a second level consisting of a surrounding balcony with oak fences as railings, and fences & torches arranged like a chandelier over the center of the room. The two levels are connected by a ladder on the wall furthest from the entrance. No cobwebs generate on the second level.
Libraries are the most well-lit rooms in the stronghold, having enough torches to prevent mob spawning entirely within them.
=== Blocks ===
Block
(both generated naturally and if silverfish enters stone bricks)
(if silverfish enters mossy stone bricks)
(if silverfish enters cracked stone bricks)
(if silverfish enters cobblestone)
== Loot ==
=== Altars ===
=== Storerooms ===
=== Libraries ===
== Data values ==
== Advancements ==
== History ==
 
Unnamed Brick Blocks.png|The first image of a stronghold that Jeb posted.
Ruins1.png|The first image of a stronghold that Notch posted.
Beta 1.9 pre3 stronghold.png|Strongholds in Beta 1.9 Prerelease 3.
== Issues ==
== Trivia ==
* There are exactly 233 bookshelves in a large library, yielding 699 books if mined without Silk Touch, which is 10 stacks plus 59 left over.
* Although strongholds do not generate above ground, they can be exposed through above-ground monster rooms or canyons.
* Sometimes, they can also be exposed underwater if they generate in terrain that is close to an ocean, or exposed by an underwater canyon.
* When generating in a buffet world, many rooms lack the outer wall layer, causing the stronghold to appear fragmented, with the exception of the portal room.
== Gallery ==
=== Overview ===
File:StrongholdUncovered1.png|The side view of an uncovered stronghold.
File:StrongholdUncovered2.png|Overhead view of an uncovered stronghold.
File:StrongholdUncovered3.png|Top view of an uncovered stronghold.
File:Strongholdgeneration.png|A stronghold generated on Superflat using Customization GUI in 12w40a and 12w40b.
File:Over.png|An underground view of the top of a stronghold.
File:Stronghold at surface.png|An end portal room generated partially above sea level, noted by the windows.
File:Tiny Underwater Stronghold.png|An underwater end portal room with no other rooms.
File:Under.png|An underground view of the bottom of a stronghold.
File:Iron Door in Stronghold.png|An iron door in a stronghold.
File:Stone Bricks in Stronghold.png|Many stone bricks in a stronghold with an iron door on it.
File:RavineandStornghold.png|Ravine with multiple ores, water and lava falls, and a stronghold bridge over it.
File:3 structures together.png|Desert pyramid, mineshaft and a stronghold generated together.
=== Rooms ===
File:Stronghold1.png|A stronghold with a fountain.
File:PillarRoom.png|A stone pillar generated in a large room.
File:Large Stronghold Library.png|A large library.
File:Library In Stronghold.png|A small library.
File:Stronghold Chest.png|A chest in a stronghold chamber.
File:Stronghold Torch Glitch.png|A floating torch in a pillar room, from a rendering glitch.
File:Floating torch in a library.png|A floating torch in a library.
File:Incomplete End Portal.png|The end portal room, with an inactive end portal.
File:End Portal Spawner.png|Finished end portal.
File:Ladder in Stronghold.png|A ladder in a stronghold library, which gives a player access to a second floor.
=== Odd generation ===
Dungeon in Stronghold.png|A zombie monster room. Though not technically part of the stronghold, monster rooms can generate in strongholds.
StrongHoldDungeon.png|A monster room intersecting a stronghold.
Ravine2.png|Canyon cutting through a stronghold.
Stronghold Mineshaft.png|A stronghold intersecting with a mineshaft.
Lava Ravine Stronghold.png|A floating library generated in a canyon over a lava lake.
RavineStronghold.png|Another stronghold cut by a canyon.
Library Mine.png|A mineshaft generated inside a stronghold library.
Dungeon Stronghold And Library.jpg|A monster room intersecting a stronghold and library room.
Stronghold-mineshaft.png|A stronghold and a mineshaft intersection.
3inone.png|A monster room, stronghold and a mineshaft in one area.
Stronghold floating doors.png|A stronghold and a cave system. This causes the doors to float.
Dungeonskelle.png|A skeleton monster room that generated in a stronghold
Dungeon in library.png|A monster room generated in a library.
EndPortalIncomplete.png|An end portal room intersected by a mineshaft.
Floorless Stronghold Library.png|A stronghold library above a cave.
Underwater Exposed Stronghold.png|A stronghold exposed underwater.
Stronghold Cave Spider Spawner.png|A stronghold intersecting the monster spawner corridor in a mineshaft.
Preset stronghold below.png|A stronghold under a village.
3 rooms stronghold.png|Stronghold with only 3 rooms.
Small Stronghold.png|Another small stronghold.
SmallStronghold.png|A small stronghold with a small library, a chest corridor and a portal room.
2way.png|End portal room in stronghold with 2 possible ways to get in. Check the image for seed and coordinates.
Ravin.png|Mineshaft along with stronghold and jungle pyramid generated in one canyon.
GlitchedMinecartChest.png|This chest minecart is trapped inside a mossy stone brick block, due to a stronghold and a mineshaft that generated partially overlapping.
Minecartportal.png|Minecart with chest generated on top of end portal frame, because there is mineshaft behind the wall.
Minecraftstoreroom.png|Two store rooms that intersecting with mineshaft. 
Libraryintheair.png|Stronghold library generated in ravine, making it float.
AmethystGeodeStronghold.jpg|An amethyst geode intersecting with a stronghold.
Active portal.png|This portal is already activated upon world generation.
Exposed portal.png|A portal room at the bottom of an ocean.
Sf.jpg|A stronghold room generated at bedrock level.
=== Other ===
File:Silverfish Near Fountain.png|Four silverfish chasing the player in a stronghold.
File:Mushrooms In Cell.png|Mushrooms growing in a cell made of iron bars.
File:Stronghold Loot.png|A chest containing three items: an apple, iron pickaxe, and iron boots.
File:Deep Stronghold Stairs.png|A staircase leading to bedrock.
File:FloatingLadders.png|A glitch where the ladders of a stronghold can appear floating.
File:Library Set Ablaze.png|Stronghold libraries can sometimes be set on fire by naturally-occurring lava.
File:Stronghold chest loot library.png|Chest loot in a library containing books and paper.
File:Live2023-03.jpeg|Ari and Efe in the stronghold library, from the announcement of Minecraft Live 2023.
== External links ==
* Eye of Ender throw plotting tool
* Another Stronghold Locator
*A stronghold and village finder for 1.7
* Python implementation to find strongholds
* (Yet another, but working) Minecraft stronghold locator
* Still another stronghold finder
* 
== References ==
cs:Pevnost
de:Festung
el:Stronghold
es:Fortaleza
fr:Fort
hu:Erődítmény
it:Roccaforte
ja:要塞
ko:근거지
nl:Burcht
pl:Twierdza
pt:Fortaleza
ru:Крепость
th:สตรองโฮลด์
uk:Фортеця
zh:要塞