'Natural' Dungeons (not just caves!)- any ideas on making them interesting?

[Tonguez]

How many of you use Caves and/or similar 'natural' features (ie not constructed by a sentient creature) as Dungeons for your PCs and what do you do to spice them up and make them as exciting as the ruins of the underground Temple of Zeb?

My current camapign setting doesn't have much room for standard 'ancient ruins' so I've been using caves when 'Dungeon-delving' is called for. But what advice do you have on making caves 'different' enough that one stalagtite doesn't start looking like any other?

PS
So far I've used the Spider Caves from WOTC

I've got Sahuagin living in the reef Coral caves

and the PCs are currently exploring an island (a coral Makatea which was raised 300 ft above sea level and whose lagoon is now a indented plateau). However the Plateau is collapsing underneath the PCs so that they have found themselves going from exploring dense jungle to being trapped in a large underground cavern with possibility of more collapses (they will I intend this to be one big trap until the whole interior of the Island has collapsed and they find themselves in the ocean...

 

[Zander]

You may want to have a look at these pics of the Jenolan Caves in the Blue Mountains, Australia. The names alone of some of the chambers should give you ideas. I think you can print the pics, so you can show them to your players and say "this is what the cavern complex looks like".

 

[jdavis]

We have had natural caves that were carved out by the ocean crashing into a cliff wall, A White Dragon made her lair there (she kept her hoard in parts of the cave complex that were under water. The whole side of the cave complex was open to the sea and freezing cold (reflex checks for slipping for anything more than slowly walking).

We also had Drow who made their tunnels in the old Lava runs on the side of a volcano, they went down half a mile and in places were extremely hot.

 

[s/LaSH]

In general, you've got two kinds of rock cave, sedimentary and igneous, plus coral formations. Sedimentary caves are limestone or similar stuff, probably very wet, because they're carved out by water, and they're the ones with stalactites and stalagmites (again, these are created by water). Igneous caves are formed by volcanic eruptions, and take the form of bubbles or tubes; such formations could concievably include crystal geodes and gemstones sticking out of the walls. Coral just grows and looks pretty on its own.

Internal cave formations could be clustered around themes. For example, you might have a cave that's really just a hole, with the 'rooms' ledges around the edge. Or you could have a cave that winds its way up inside a clifface, giving you increasingly better views of the valley below. Or a river that rushes into (or out of) a cave; who knows where it goes (or comes from?).

Then you could advance to combination caves, such as a lava tube that's quite old and is home to enough moisture to create stalactites, or a coral structure embedded beneath a lava flow. The interactions between the two are bound to be interesting.

Then there are the plain weird ideas. Here's a few:

A massive iceberg drifts up to the archipelago. It's got its own cave structure within it and could well bear strange creatures from another land...

Giant ants create a mighty hive from mud and straw; the structure is strangely organic and has a definite design vision behind it, although what that vision is is not immediately apparent.

Mini-plateaus: Ever see cartoons where the ground breaks, and everyone finds themselves on independant little pieces of ground with bottomless chasms around them? Try one of those. It could be rocky ground interspersed with ravines, it could be fragments of stone on a river of lava, it could be rafts tied haphazardly together on a shark-infested sea. All that's important is that the 'pieces' form rooms, and the gaps form barriers that are more or less impassable, just like walls in a normal dungeon.

 

[Drawmack]

Generally I use maps from existing caves. Being that I live in the Pocono Mtns. (an area carved by glaciers) I am privy to many caves. I will often explore and map caves then use them in the game. Here are a couple of tips on making caves unique without killing the atmosphere of a natural cave.

I am not a geologist, this is information that I've picked up from a single class in geology and from being a hobbyist, it could be wrong.

1) What type of rock is the cave made from? The rocks that compose the caves do not only add color and shape to the surroundings but also smell. Go to your local new age shop and pick up some different types of stones that make up caves. Take those home use sandpaper to rough them up. Then get them wet and keep them in a damp container (cool whip containers work well) for a couple of weeks. Keeping them in the fridge works well to keep the mold down but let the smell of the rock permeat the container. Then you can pass that around the table so show everyone how the cave smells.

2) What created the cave? There are generally two ways that a cave can be formed underground streams and quick land movement. These two caves have very distinct features. The underground stream makes a smooth flowing cave system. No real drop offs, smooth walls and this type of cave also usually has a lot of water in and around it. Puddles abound, the drippings on the ceilings. Some really neat things happen when the water that drips has calcium in it. The land movement caves are generally very rough and jagged. Sometimes they are wet but usually they are dry.

3) Interesting rocks and plant life? Maybe a room will have phosspheressent deposits in the rocks with can make the room glow just about any color. When there is no light for photosynthesis you get some very interesting plant and animal life as well. For example there is one type of cave fish that has clear skin and no eyes. You can't even see them in the water unless they ate recently or need to defecate.

4) Are you sure these caves are natural? All that gold, silve, platinum and bronze that makes your coins came from somwhere. These could be long abandonded mines that are so old they seem natural. That is until they start colapsing because the supports are worn out or they let out into an abandonded dwarven city.

Here are some resources for you.
http://www.caves.org/
http://cavern.com/
http://www.sealioncaves.com/
http://www.nps.gov/orca/
http://www.sat.dundee.ac.uk/~arb/speleo.html
http://www.polarcaves.com/
http://www.culture.fr/culture/arcnat/lascaux/en/ (click on the picture below the title to make the site appear)
http://w3.one.net/~charlie/2.html
http://www.wookey.co.uk/
http://www.amazingcaves.com/
http://www.nps.gov/wica/Cave Geology 01.htm
http://www.cedcc.psu.edu/phillygrotto/geology.html
http://www.guanopage.com/info/cavegeo.html

Hope that helps.

 

[CMonkey]

Have a look at the computer game Rune by Human Head Studios if you can. (You should be able to get the PC version v. cheap now.) It has some excellent cave structures.

CM.

 

[Ashy]

You might also want to check out the following article by Monte Cook, after his trip to the Emerald Isle!

http://www.montecook.com/arch_dmonly18.html

 

[Fast Learner]

Here's a link to a recent episode of Nova about the "Mysterious Life of Caves" that has some information about some amazing acid caves, filled with sulfuric acid and creatures the creatures who thrive there.

The wind creates some cool cave complexes in desert areas. Here are some pics of what simple ones look like. While each individual cave isn't very deep, a mountain can be riddled with dozens or even hundreds of them, and it's not hard to imagine a tribe (or even a civilization) of fantasy peoples living in them.

In addition, slot canyons provide some visually incredible caverns and passages.

 

[Ran]

Well, if it is an existing cave, make it alive, there are creatures living there, there is a whole chain of hunter and prey, make it logical and they are gonna like it.

Of course you can also put some intelligent inhabutants, the top of the chain...

Else, take the maps everyone else posted links to, that would be just great, and remember, natural caves are complexes that you can hardly find your way on, confuse the players and they will feel that it took quite some time for you to design it... hehehehe...

 

[astralpwka]

The last cave I was in was an ice cave. The opening of the cave acted like a refrigerator, keeping the cave always cold, and as the water slowly collected in the cave, more and more ice forms. The entire floor is like five feet deep with ice, plus with a few really long drops (with more ice). In one spot there was even a bear skeleton preserved in the ice going back a bunch of thousand of years.

The great thing about this cave is its a part of the Idaho desert in the middle of lava rock. Would be interesting in an adventure to come across an ice cave in such a setting since you wouldn't think about the combination like this much.