Minecraft wiki entry for Stronghold, associated text: A zombie dungeon. Though not technically part of the stronghold, dungeons can generate in strongholds.
A dungeon intersecting a stronghold.
Canyon cutting through a stronghold.
A stronghold intersecting with a mineshaft.
A floating library generated in a canyon over a lava lake.
Another stronghold cut by a canyon.
A mineshaft generated inside a stronghold library.
A stronghold and a mineshaft intersection.
A dungeon, stronghold and a mineshaft in one area.
A stronghold and a cave system. This causes the doors to float.
A skeleton dungeon that generated in a stronghold
A dungeon generated in a library.
An end portal room intersected by a mineshaft.
A stronghold library above a cave.
A stronghold exposed underwater.
A stronghold intersecting the spawner corridor in a mineshaft.
A stronghold under a village.
Stronghold with only 3 rooms.
Another small stronghold.
A small stronghold with a small library, a chest corridor and a portal room.
End portal room in stronghold with 2 possible ways to get in. Check the image for seed and coordinates.
Mineshaft along with Stronghold and Jungle pyramid generated in one canyon.
This chest minecart is trapped inside a mossy stone block, due to a stronghold and a mineshaft that generated partially overlapping.
Minecart with Chest generated on top of End Portal Frame, because there is Mineshaft behind the wall.
Two store rooms that intersecting with mineshaft.
Stronghold library generated in ravine, making it float.
An Amethyst Geode intersecting with a Stronghold.
This portal is already activated upon world generation.