Strongholds

One of the first structures made in the plugin. May be slightly rusty compared to the others.

Silverfish Den

Contains a silverfish spawner, silverfish egg blocks and chests

Library

Spawns chests sometimes. Will always have 2 levels inside, with a staircase.

Abandoned Nether Portal Room

Just a nether portal frame that is broken. Entrances to this room are blocked with wooden planks. The fire doesn't normally spawn, it was placed to illuminate the room for the picture.

End Portal Room

The main portal room. Generally the look of it is standard, though the width and height may change. Contains a block depiction of an ender eye on the ceiling, and a lava fountain beside the portal.

Prison

A prison room that spawns chests and some skeletons. Consists of 2 levels, and only spawns in rooms that are sufficiently wide and tall.

Supply Room

A room that contains some loot, along with some piles of blocks.

Trap Chest Room

This room spawns with tnt pressure plates, with a trapped chest at the center. Sometimes, there is tnt under the trap chest, though sometimes there isn't.