There are many types of natural generations in Minecraft, and strongholds are one of them. Strongholds hold many types of treasures, but they can also be very dangerous, if the player is not properly prepared.
There are all kinds of mobs that spawn in these strongholds, but the many treasures a player can find make it worth the risk.
Locating a Minecraft stronghold
Locating a stronghold can be a little tricky.
A player must have at least a couple eyes of ender, which can be crafted from ender pearls (dropped by an enderman) and blaze power (crafted from a blaze rod; dropped by blaze's).
After acquiring the eyes of ender, the player must right click with it in their hand, and the eye of ender will float away. The player must then follow the direction of the eye of ender, and continue to throw them as they make their journey (some eyes of ender may break along the way).
When the eye of ender no longer moves when throwing it, but goes straight up, and back down, they're in the right place. Right under that spot is where the stronghold lies, waiting for the player to explore.
Many mobs can be found lurking around these strongholds, so players should be careful when exploring one. Any type of mob that spawns in darkness can be found here. This includes zombies, skeletons, creepers and all the rest.
Another mob that can be found in Minecraft strongholds is silverfish. They spawn throughout the stronghold, mostly in silverfish blocks.
Throughout strongholds, players will find that there are a multitude of rooms waiting to be discovered. Every room generation in a stronghold will be different, and have its own unique items.
The hall is one of the many rooms a player can find. It is used to link up other rooms and may also contain a fountain.
Another one of the rooms found here is the jail. The jail doesn't have much in it besides a couple of cells, which can house some monsters.
The library is another room in a Minecraft stronghold. Here, a player will find plenty of bookshelves, and sometimes, even a chest with some neat loot.
A player will also find a lot of empty rooms throughout the stronghold. These rooms hold absolutely nothing, and have no use, other than connecting rooms.
The final and most important room is the one housing the end portal. To activate the end portal, a player will need six eyes of ender, and they'll be on their way to defeat the most dangerous mob in Minecraft.