A Stronghold is an underground structure found in Minecraft after Beta 1.8, or officially after 1.0.0, only three spawn per map, (and one on the Xbox and PS3 editions.) Most Strongholds have several Monster Spawners, (mainly Silverfish) an abundance of Stone Bricks, Torches, Chests with somewhat randomized loot, Stone Slabs, and blocks found mainly underground such as Cobblestone.
A hazard worthy of note that is found inside Strongholds is the Silverfish; these spawn from certain almost impossible-to-discern blocks that look the same as their surroundings, but mine somewhat slower and instantly spawn several Silverfish upon breaking. Some of the items commonly found inside a Stronghold include Coal, Apples, String, Compass, Paper, Books, Iron Bars, Redstone Dust, and sometimes a Clock or Gold Ingots.
It is possible and relatively common for Underground Ravines, Abandoned Mine Shafts, and Dungeons to intersect a Stronghold. When generated after 1.0.0, Strongholds also contain a portal room with an inactive End Portal, which when activated with 12 Eyes of Ender, can be used to travel to The End.
What you need
When you are exploring a stronghold, it is advised to bring some useful things you need if in a stronghold. You will find some good luck in there, but there can be bad luck while without any useful supplies.
You will need:
- Pickaxe: there might be mossy stone bricks or ores (extremely rare) that comes your way.
- Sword: many mobs, including Silverfish, might get in your way, so be prepared with a sword.
- Eyes of Ender: most important resource while exploring and finding a stronghold; you will need these to find the stronghold, activate the End Portal, and find your way back on the land.
- Health Potions: your health may be running out due to the hostile mobs. Regain the health by using health potions.
- Iron or Diamond Armor: these kinds of armor are strong enough to keep you alive and have more defense.
- Bow and great amount of arrows: this will be convenient later on in The End while fighting.
- Food: all that fighting & exploring had made you lose several hunger points. Make sure you have foods that restore at least 3 or more hunger points.
- Map: if you get lost, you can use your map.
- Compass: if you think the map does not work, you can bring a compass along to see what direction you are in.
- Torches: like caves, they serve little light by dangerous lava. Make sure that you bring plenty of torches.
- Clock: this is only for the Overworld. If dawn turns to dusk, mark every area with torches so that no hostile mobs can get in your way. The clock is useless in The End, as there is no Sun or Moon.
- Bed: if you place a bed in a stronghold, and if you die, you're still in the stronghold.
Mobs that spawn inside of Strongholds are mostly Silverfish, however, Skeletons, Zombies, Creepers, and Endermen can spawn inside due to a lack of light, especially in places that caves or ravines intersect.
While there is no predefined template or blueprint for a Stronghold, there are serveral rooms that may generate in a Stronghold. Here is a list of rooms and what they contain:
- Hall: Big room that may contain a fountain. Often used as the entrance and/or to connect other rooms.
- Jail: Empty rooms behind, Iron Bars, Iron Doors, (Usually opened) and Buttons.
- Small library: Bookshelves, Wooden planks, Chests and Cobweb.
- Large library: Same as a Small library but with an added floor above, with a balcony and Fences and Torches arranged in a in a chandelier-like style. Both floors are connected by Ladders.
- Empty rooms: This is self-explanatory, often generated to the sides of Halls.
- End Portal Room: The room contains a End Portal and a Silverfish spawner.
As a Base
If you visited a Stronghold multiple times and know what is where in the Stronghold, you might want to use it as a secondary base. This has its advantages, but also disadvantages:
- If you play on a server, it is very hard to find for griefers if they don't have Eyes of Ender.
- You don't have to build or dig a whole base because the map generator has already done the work for you!
- There is plenty of space to store your loot.
- A handy tip if you are moving to another location: Take anything you might want to have in your new base, including bricks!
- If you get lost (in the Overworld), you can find your base by using Eyes of Ender, so remember to take some when going out.
- If you need to go to The End (if the server does not have a warp feature that goes to The End), there is always one nearby.
- You will need lots of torches to ensure that no mobs will spawn. Or, you must always be ready to fight.
- However, as you (assumingly) already have explored it thoroughly, there are likely already a lot of torches around.
- If you are in SMP, the last advantage also counts for other players armed with Eyes of Ender.
- Since they are often exposed by Ravines, Abandoned mine shafts, and Dungeons, it makes it easier to find for griefers.
- If you are moving and following the tip named above, mining some Stone Bricks might awaken Silverfish.
- An easy way to discriminate between normal bricks and Silverfish bricks is to see how fast it mines with your hand. Silverfish bricks are destroyed in 3 seconds, even using your hand.
- For some reason, the stairs leading to sections are Cobblestone Stairs instead of Stone Stairs. Only the ones that lead to the Portal, are made of Stone.
- End Portals become useless if there is an Abandoned Mine Shaft or a Ravine cutting right through it (As at least one of the 12 portal surround blocks tends to be destroyed on generation).
- There is a possibility that you will be unable to locate the portal, because it will be hidden inside the stones.
- It is extremely rare, but possible, for a dungeon to be just outside the portal room, thus cutting off the rest of the Stronghold or not spawning it.
- It's extremely rare but if you go to the portal and go in it, you will go to the Nether instead of The End.
- If a stronghold is found at diamond level, there is a possibility that it will cut through bedrock. Usually staircases going down to here are just an empty room.
- Strongholds can sometimes spawn under oceans or other bodies of water. This occurence can make them hard to access.