Dungeon Locations

[Koo Rehtorb]

I need ancient ruins for fearless adventurers to raid. Monster dens are an old standby. Crypts, wizard's laboratories, ancient temples, cult lairs, etc.

But I need some more weird and unique places to throw in there as well that aren't just the same old thing.

[Yllin]

Here's what i came up with after some thinking:

A shipwreck: A huge ship hit coastal rocks. It is damaged beyond repair and stuck on the cliffs, but a large part of the ship is still intact. What goods did it sail and what happened to the crew?

Continuing the theme, an abandoned shipyard: a large place with internal facilities of various sizes and purposes. You would probably want to search for some actual shipyard maps, they look pretty cool. Being a place with large hangars and access to outside, this could be a perfect base for a dragon.

A lighthouse: probably not that exotic, but I love the flavor. Probably some disaster happened to the keeper while no one was around, but what exactly? I would enjoy having something mysterious and dark here. Bonus points if the door grants near-perfect protection unless open from inside voluntarily.

Abandoned city facilities could make nice dungeons.
A jail is the most obvious: it is literally a dungeon. Hospitals could bring horror moments, and so could schools.

Speaking of schools, something like Hogwarts, with a lot of secret rooms and passages, would be an interesting place to play around.

A golem factory, with some obvious golem encounters.

A huge greenhouse: overgrown with vegetation, with evil lurking deep inside. Characters' field of vision is severely restricted with exotic plants, and shadows are playing tricks with perception. Bonus points if you give characters a reason to dive in instead of burning the place.

Sewers are no kind of exotic, but somehow you missed it in your post, so I decided to remind you of the possibility.

A Labyrinth: like that one with Minotaur. You can basically take the myth and reflavor it to your needs.

A military base: I'm not sure if it would make a lot of sense in a dnd setting. But it would make a great dungeon: a place with fortifications and defenses still active, the staff ceased communication with external world, and like nobody knows what secret military research was conducted inside. Mutants? Mind control? Bombs?

A vampire's mansion. This one is pretty much classic, but kind of awesome.

A net of ice caves: natural cavities inside a thick layer of ice.

[Koo Rehtorb]

Some good stuff there! I especially like the greenhouse. And of course how silly of me to forget to include the sewers.

[Stan]

Inside a dead titan riddled with parasites and scavengers. Can you find the massive royal diamond now in his gizzard?

An old battlefield, complete with wooden towers, trenches, booby traps, ground difficult with piles of ancient bodies and rusted pointy weapons everywhere.

A palace, either abandoned, partially abandoned (going with the common dying race trope), or long abandoned. It's no mere castle but has opulence everywhere and things meant to amuse the bored rich. Probably defended by exotic automata that show off wealth as well as deadly force (Byzantines had things like a tree of singing birds, roaring lions, and mobile thrones - and that was without magic).

abandoned mine

old amusement park and/or zoo. Golem clowns gone insane. Imagine the truly strange specimens a fantasy royal zoo might collect that now roam the grounds, desperate for food.

Inside someone else's dream (perhaps an immortal's?), with a shifting landscape, odd transitions, and things that just don't make sense.

[The Great Wyrm]

Inside a dead titan riddled with parasites and scavengers. Can you find the massive royal diamond now in his gizzard?

The "Anatomy Park" episode from Rick and Morty has a good take on this.

[Lacuna Caster]

@Yllin: Neat suggestions.

About the greenhouse- there is a slight drawback to any dungeon where the PCs (and monsters?) can go crashing through transparent walls, since dungeon design relies heavily on restricting nodes of interaction with the world. (PC sees treasure chest in adjoining room. Crashes through wall. Beholder in room after that spies PC. Hilarity ensues!)

[Stan]

About the greenhouse- there is a slight drawback to any dungeon where the PCs (and monsters?) can go crashing through transparent walls, since dungeon design relies heavily on restricting nodes of interaction with the world. (PC sees treasure chest in adjoining room. Crashes through wall. Beholder in room after that spies PC. Hilarity ensues!)

It's fantasy. The wall could be made from transparent unbreakium because the owner was tired of people throwing rocks. It might be cool to be able see through walls (except some might be overgrown with moss or mildew as the watering system is still active). Then you'd know that there was a gem on a throne one room over but you'd have to figure the best path to get to it.

And that one wall with treasure on the other side is actually a gelatinous cube with stuff inside it.

[NRSASD]

You could use an abandoned trading post on the frontier, which would be a small fortified dwelling designed to handle large volumes of traffic. Any treasure found there is more likely of the trade good variety, thus posing a problem to our intrepid PCs. If they want the 10,000 gp in cash, tell me how they're transporting 5 tons of raw ivory back home.

Monasteries are another old but good standby. I'm differentiating them from temples because they tend to be larger and have all the facilities needed to support a thriving monk population.

As opposed to a shipwreck, a ship is another possibility. A perfectly functional yet apparently unmanned ship drifts into port. Is the hold full of undead, sahuagin, or plague? Is it a decoy launched by pirates? Is it pulling a Marie Celeste? Who knows?

Related to hospitals, insane asylums are a solid choice. Definitely on the horror side of things though.

One you haven't mentioned but is absolutely hilarious is the gold standard of traps and unfair death: the Thieves Guild. It's the dungeon where people who spend their lives disarming traps, stealing things, and breaking into every dungeon they can find were told to "make this place secure by YOUR standards".

[Ossian77]

Just a variant of the classic room-sequence dungeon, but how about the good old CATACOMBS! Deep, layered like a cake, with minions buried in shallow vaults and alcoves on the first levels, and progressively bigger cheese being buried deeper underground. More opulent, but also more visibly decadent. Denizens don't even need to be undead.

Perhaps various kinds of ooze (explains the polished look?) or maybe fungine creepers gone worng in a colossal way? (even sentient?) or zerg-like, with a huge ass hive mind? Or totally devoid of all life ...except for the security personnel, if that counts as life. All automated, imagine floating eyes, gas-spore (floating eyes/anti-human landmines), tankers (e-la- ED209 ?) sweepers....

[MrZJunior]

Ruined ancient Roman style baths would be a solid choice. Lots of statues that might come alive, enough water to grow any sort of nasty plants you like, drains and pipes that make for cool secret passages, and many. possible entrance points from outside. It would also have unusual or awkward loot like large chandeliers or vases. You would probably need goblins or some such creatures to have moved in and settled.

[Leewei]

Flooded grasslands with swift, treacherous currents. Herds of large animals are struggling to cross. Suddenly, something not far from the PCs eats one of the animals. Whatever it is, it's big ...

A series of large plateaus, shrouded in dust clouds, where lightning arcs horizontally from one to the next.

The playroom floor of a toddler Titan (its pets are ferocious, but shouldn't be killed).

(Stealing this from Avatar.) A great library, that only rises above the sands of a huge desert once every hundred years.

[Jay R]

Abandoned rice terraces - a multi-level series of foot-deep swamps, each a separate ecosystem, working up a mountain.

A completely abandoned, but not ruined, village. There's even food still cooking on the stoves. Where are the people?

After an unexpected and devastating flood, a deep canyon where a small river had been before. There are no plants yet, but there could be flotsam, and entrances to caves never seen by the surface world before. Possibly seams of once-buried ores.

How long would it take the adventurers to realize that the building they are in is not a carefully trapped dungeon, but an old, abandoned trap factory?

[JAL_1138]

A hillside with small boulders laid out to form a grinning skull. Prodding the hillside with 10ft poles reveals an entrance to a certain (in)famous tomb...

A recently-abandoned farm, the occupants having fled the onrushing orc horde (who, incidentally, are about to show up with their spears sharpened and bellowing war cries...)

Abandoned museums, or armories of obsolete weapons and armor.

An active circus of evil (to contrast with Stan's suggestion of an abandoned amusement park). Demons, cultists, assassins, and suchlike masquerading as a circus troupe.

City guard station and barracks hiding a sinister secret. Think medieval Resident Evil 2.

A dense forest full of gigantic trees, thick underbrush, twisting mazelike paths, and strange monsters, akin to Mirkwood.

Back alleys of the slums, perhaps in the midst of a gang war. Or perhaps beset by some supernatural evil. Think of the (now-bulldozed) Kowloon Walled City--but gone wrong, such as its incarnation in Shadowrun: Hong Kong.

The streets, alleys, buildings, and undercity of Sigil, the City of Doors.

The lower planes. Carceri might be an interesting one.

A dangerous, winding mountain pass, riddled with switchbacks, false paths, dead ends, etc.

[Lacuna Caster]

It's fantasy. The wall could be made from transparent unbreakium because the owner was tired of people throwing rocks...

Yeah, I was going to say "and medieval glass is so expensive"... when I remembered that dungeon economics was never terribly grounded to begin with. :P

[Jay R]

Pompeii - a town wiped out by a volcano, completely buried in volcanic ash.

An area that has been covered by a glacier for ten thousand years, now suddenly open again because the PCs just used several fireballs in a battle against frost giants.

In both cases, you need to decide what treasures survived the catastrophe, and what dangers are lurking. Note that in a fantasy game, you can decide that frozen monsters are revived, or that some species can survive being buried by ash. Unearthing the bodies of trolls can be quite unnerving when the "bodies" suddenly attack.

[Âmesang]

It's fantasy. The wall could be made from transparent unbreakium because the owner was tired of people throwing rocks.

As a bit of a reference, the D&D3 adventure, The Sunless Citadel, had a transparent iron ore called "nephelium."

EDIT: And there's also the classic "glassteel."

[Lacuna Caster]

Ruined ancient Roman style baths would be a solid choice. Lots of statues that might come alive, enough water to grow any sort of nasty plants you like, drains and pipes that make for cool secret passages, and many. possible entrance points from outside. It would also have unusual or awkward loot like large chandeliers or vases. You would probably need goblins or some such creatures to have moved in and settled.

I really like this idea for some reason.

[Professor Chimp]

A super-secret underwater volcano lab ... in space!

Don't laugh, a campaign I once ran had one of these. Good times were had.

[Fishybugs]

The favorite dungeon location I've played in was a castle my DM created. This castle was upsteam from a medium sized town, and the river had been increasingly polluted. A team was sent to investigate what was going on. As we got closer to the castle, animals were acting strange...out of character. We were never assaulted directly, but there were clues that things just weren't right.

We get to the castle and find it's mildly broken down, and are attacked by some lions. In a castle nowhere near a jungle or forest. There are alchemy jars and all sorts of things going on. The lions had weird properties. I'm can't remember all of them, but I do remember they were almost elastic. They squeezed themselves through windows way too small to get through.

It turns out the wizard who was living in the castle was experimenting on animals there. He had died, and the animals eventually got out of the cages. The concoctions were left around and the animals drank out of them, spilled them, mixed them, all sorts of things. It was these which were polluting the river (I don't know how enough got in to pollute the river, but hey....magic!).

It was fun because you run into an animal and think you know what it can do....but there's always a twist. It gives you a chance to mix things up and surprise the rules lawyers and over-optimizers who have the Monster Manual memorized.

[AMFV]

Any kind of natural formation that's been taken over. From a Lava Flow to an Ice Cave, could make for some interesting delving. Partially because you have all kinds of natural hazards, and partially because you don't necessarily have to enforce a logical structure to the delve. You could also have areas where PCs might have to melt or tunnel to get through, and sometimes backtracking might be impossible, particularly if ice melts or breaks or if there's new lava flows that reoccupy old tubes. You'd also have the advantage of having certain monsters that would be much better equipped to deal with those hazards than the PCs.

Other options include: A Magic Maze a la Labyrinth, you could make it stone or Topiary or something. Have the walls able to move or magically shift when the players are inside. Possible courses of action include prepping several different configurations for the players to see, so that they can do some mapping, but won't notice how the shifting is working until it's too late. Minotaurs are of course optional in this maze. Of course you'd need ways to keep them from just bypassing it, by climbing or cutting (in the case of a topiary maze), although you could have direct methods against these (roofs or magical protection of the plants) indirect options (the maze adjusts to your movement and shifts upwards, or the plants regrow in different ways and directions) which could serve to further disorient the players.

One could also do something like an underground river that flows around, that produces natural caves. This will have lots of tight squeezes and light will be a problem (since people will get doused) this might not be more than a nuisance in D&D, but in other systems could be quite nasty. Also the idea of old terrible things living in the roots of mountains is a pretty old idea as far as stories go and could be quite interesting to explore.

The interior of giant tree. This is pretty videogamey, but it could certainly be adapted for standard dungeon delving. And you could certainly have a lot of fun with the whole living interior as well.

[DigoDragon]

An area that has been covered by a glacier for ten thousand years, now suddenly open again because the PCs just used several fireballs in a battle against frost giants.

I once sent a party into a dungeon that was carved out of an iceberg. It was a fun little excursion for them; cold, dark, and frigid. Nearly drowned two PCs in a trap that was basically a room with a break-away wall to let in the sea.

[Vrock_Summoner]

This isn't my original idea, but I remember it quite fondly. Instead of a dragon inside of a dungeon, why not make a megadungeon inside of a supermassive dragon? Inside you'll find dragon-shaped antibodies with normal-sized dungeons inside them. Your weapons are still too small to kill the inner dragons (who are the size of whole dungeons), so you beat them by clearing their dungeons as you work your way through the larger dragon dungeon. Each miniature dragon is filled with oozes and proteins taking shapes based on their function and maybe what the dragon has eaten recently, with entirely different ecosystems from one antibody dragon to the next, with a variety of supernatural effects enchanted into living effects, and horrific shadow-based and consumption-based monsters scouring clean whatever the antibodies and digestive system of the dragon can't harm, working as scouring gut bacteria.

[Cluedrew]

Inside your own mind.

Inside someone else's mind.

On top of a flotilla of ships, all lashed together.

At the bottom of the lake (or in the center), water held back by some strange force.

Atop a lake of fire.

[Jay R]

A cold-sleep colonizing space ship has crash-landed. The cold-sleep settlers are in containers that are automatically set to awaken them when another warm-blooded creature enters the room. So about a half-hour after the party passes through, detecting no life, there will be a growing horde of people between them and the exit - of a race they've never seen before, speaking a language they do not know.

Meanwhile, the settlers, finding no doctors there to help them revive, will naturally conclude (correctly, by the way) that the ship has been invaded by aliens.

Hilarity ensues!

In the longer term, this could be used to introduce a new race, or even a race very similar to a known race, but far more civilized, intelligent, and technologically advanced.

Gnolls with machine guns? Orcs with lasers? Tieflings with tasers? Ogres on motorcycles? Goblins with modern mining tools, who have already conducted a full-scan of metal deposits in the planet?

[JAL_1138]

A cold-sleep colonizing space ship has crash-landed. The cold-sleep settlers are in containers that are automatically set to awaken them when another warm-blooded creature enters the room. So about a half-hour after the party passes through, detecting no life, there will be a growing horde of people between them and the exit - of a race they've never seen before, speaking a language they do not know.

Meanwhile, the settlers, finding no doctors there to help them revive, will naturally conclude (correctly, by the way) that the ship has been invaded by aliens.

Hilarity ensues!

In the longer term, this could be used to introduce a new race, or even a race very similar to a known race, but far more civilized, intelligent, and technologically advanced.

Gnolls with machine guns? Orcs with lasers? Tieflings with tasers? Ogres on motorcycles? Goblins with modern mining tools, who have already conducted a full-scan of metal deposits in the planet?

Include vegepygmies and a froghemoth and you've got Expedition to the Barrier Peaks.