Sunday, 21 June 2009

Sunken Cities

When I first read Dragonlance I admit to being massively confused by Xak Tsaroth, the city that sank beneath the Earth. Not into the Earth via being sited on top of a massive landslip, but actually inside it with a roof and everything. How on Earth did that happen?

The concept crops up a lot in fantasy, not simply many strata of compressed matter from the leveling of old areas of the city but another city built on top but allowing for "headroom" underneath - so that the old city is as it was but just with a roof. The Lone Wolf gamebook The Cauldron of Terror does the same thing and drifting away from pure fantasy we have Mega-City One in Judge Dredd where the older New York exists as an inhabited subterraenean world.

I've never understood the practicality of how this works. How do you simply put a roof on an existing settlement and build ontop?

I always thought I was missing something so out of a sense of mischief I did something possibly rash - I asked 4chan.

Actually we got some really good discussion and justification for how this could come about in a plausible environment. Selected highlights follow;

An angry giant took an enormous crap on a city.
Then the crap dried out in the sun and formed a hard, calcified strata over the city. Yeah, I think I can make that work actually...

This suggestion played with the idea that yes, under the city are different strata of detrius from differing ages of the city, but add typical xD&D underground burrowers and some circumstances that allow for the lower strata to vanish...

The same way it works in the real world, City sits around for a long time, something happens, people leave city, dirt etc. slowly piles up around constructions. Or it's a part of the city that slowly gets taken over by.. well trash and dirt and debris from construction, if you go to alot of old european cities you'll be able to find underground ruins, most of them are filled with dirt though, but there are examples of 'houses' that have been excavated several meters below the current surface, where trash and dirt has simply been piled on top of eachother and the city has 'risen' like that.

Now add that there are tons of monsters in D&D that can excavate old underground cities and live in them, and there you go!

The rubbish-filled streets could work if the later construction ontop of it is more solid than the older stuff - say primitive cement or something. Then, as the lower strata rots down, it forms a void under the newer city so the PCs can sneak in, explore the old ruins while still having some headroom.
City is built on unstable ground. Heavy construction deteriorates the quality of the ground. City begins to sink. Eventually abandoned. Mud and dirt floods the city and buries it. Harder layer of soil appears on top. Mud and dirt that flooded the city is drained somehow.
Could just drain through porous rock or be washed away by groundwater, meteoric water or even an underground river. I think a river running through a city - for added effect at right angles to the initial canal/river system - would be pretty cool, but the drainage is probably the most likely answer.

Or we could have the original city pre-dating an Ice Age

I'm trying to work out a method via natural occurence. It's hard to justify a lot of them, but I'd say you definitely have to possibility of a volcanic eruption or even the collapse of an empty volcanic structure the city is built upon. Another thought would be glaciation and isostacy causing the city to sink beneath the waves. It collects debris and after the ice age ends resurfaces buried under shale, limestone, sandstone, etc - marine rocks.
Yeah that might work, once the Ice Age is over and the World warms up, the lower part of the city-engulfing glacier melts (closer to planet's core) but the upper surface remains frozen with rocky build up above it - then you have the surface world, permafrost below it, solid glacier, then a massive cavern and a ruined city on the floor of the cavern.

Exotic air corals...

You could try saying that some sort of land-coral organism ate up the city, starting from the bottom, and avoiding the shady indoors, slowly building up around the buildings. It would grow too fast, and it could be slightly poisonous, I'm thinking rashes and stuff, so that it would be just simpler to leave. In the end, the organism dies after engulfing the city, and within lies a nest of empty buildings and makeshift streets that were closed off to the coral by tunnelling through them and building overhanging roofs and walls.

Staying with wild flights of fantasy

A more fantastic approach: "Swallowed by the earth"; Maybe eaten by a great "beast or creature" which then "sleeps" or is slain. Imagine some of those mountain ranges, for instance, that were supposedly formed by giants struck down or whatever.

Meanwhile at the edge of the desert...

Say a city on the edge of desert, that over the years became more and more buried with sand, the citizens were not willing to move so they adapted, roofing over open spaces, creating sealed passage ways that kept out the ever present sand. Eventually the sand won out though and all your left with a traverseable city buried beneath the dunes.

Of course that city would then expand upwards and the lower passages could be abandoned and then if some form of evil or vermin moves in the city authorities might order all entrances/exits to the old levels sealed.

Something fell on it but didn't crush of all it...

I would suggest that a city was built underneath a giant rock overhang, and a cataclysmic earthquake brought it down on the city, but at an angle so that portions of the city were covered, and sheltered from the downpour of the rocks(think of the lion king. remember how the pride's den was all fucked up in shape? kind of like that, but on a bigger scale and no homosexual lions). The Earthquake caused a physical rift in the ground, and water from a nearby lake or ocean smashed in and drowned all the survivors, bringing in tons of silt and water, filling in the small places between the rocks, and calcification slowly solidified the rubble into a more permanent, solid structure.

Fast foreward 300 years, and the same spot has been chosen as the spot for a new city, for the same reason the original city was there. Tactical advantage, proximity to trade routes, what have you. Eventually all the water under the giant rock overhang dries up, and the ocean recedes back to it's original location due to the natural order of things. Strange ghosts and drowned undead come out of the ground, adventurers are hired to find out wtf is up.

Some good stuff from 4chan. Who would have though it? Thanks, Anon!

1 comment:

  1. What was supposed to have happened to Xak Tsaroth was similar to the last suggestion. Only a small portion of the city sank into the ground during the Cataclysm, and the steep rock walls that were created around that section as it sank then partially collapsed inward, forming the roof (the cavern is much higher than it is wide). See this map of the entire pre-Cataclysm city, and compare with this one showing the parts that became the ruins featured in "Dragons of Despair," (the lower left half of that map is still above ground, while the section to the upper right became the underground ruins) and this one detailing the underground city. Only areas 1, 2, 3, and 6 on the first map actually ended up in the cavern.

    Note that as it subsided, the Palace District was also displaced several hundred yards to the south and east (towards the lake shore), such that the Great Plaza ended up directly below the well in the plaza south of the Temple Mishakal. None of this is especially plausible for a real-world Earthquake to do, of course, but in a tectonic event on the fantastical scale of the Cataclysm, all bets are off -- especially if the Gods take a direct hand in influencing certain aspects of the event (they wanted the Disks of Mishakal preserved for the future, after all).

    Also, since the original city was built around a deep crater or rift lake that drained through an underground stream into the Heartgaard river a few miles to the east, it makes sense there might be caverns under it to begin with. During the Cataclysm, all the land to the east of the Heartgaard subsided dramatically, and west wall of the Heartgaard gorge became the coast of the New Sea -- compared to that, the quake that ruined Xak Tsaroth and swallowd its Palace District was small potatoes.