The Twaney Stack

Twaney was, in its day, the largest town in the south of the region, sitting on the northern edge of Great Tullah.  Built on a series of flooded tunnels which did something for those underground (we assume, aside from spewing awful fluids into the swamp) and out of mostly lashed-together platforms of cypress wood, the town had the distinction of being the worst place in Big Charry.  Today, the place maintains interest only because there are surface structures left by those underground; waste processing facilities, most likely, and there is a possible way to the underground itself: a wide shaft in the center of town, 50' tall at the surface, but leading almost half a mile down into the earth.  This is the Twaney Stack.

There's a catch, though, with the Stack.  Every so often, it erupts in fire, blowing 30 feet into the sky at a temperature that the locals used to leave their dead along the rim of the stack and count on the bones being reduced to ash along with the flesh.  The interval is variable, ranging from a little over 7 hours to as little as 38 minutes.  So far, there seems to be no way of knowing when the stack is going to blow, and while some folks have attempted anyway, those who have returned report that, at the bottom of the stack, there is a vast, glassy chamber and a passage that goes more than 38 minutes on foot to the north, with no sense of where the flame originates.  Many have not returned, and there really is no way to tell whether they got caught in the flames, lost below or ran afoul of something else in the underground.  The flames last anywhere from 6 to 36 minutes, in 6 minute intervals, and even the shortest intervals are sufficient to render a person completely to ash.

If this were not enough to dissuade prudent explorers and draw reckless ones, there are persistent legends among the Twaneyfolk who escaped the town (most went with the Cray, but a few made it up north to the cantons), of a settlement of the diseased and wretched of the valley that spread out south from the town into the swamp on rickety platforms and questionable rafts.  People that even Abaddon would not take in (or, as some say, people Abaddon spit out).  There were, at one time, winding docks, choked with clouds of black flies, snaking their way deeper and deeper into the swamp, and the poor souls at the outskirts of town were the ones able to still interact with the relatively normal folks in Twaney proper.  From there, you get stories like crocodile cults, hallucinogenic swamp fruits that burned or rotted the lips of the habitual users, and inbreeding or interbreeding so profound, it created a new species with every birth.

So Twaney is not as popular as it might have been in terms of an explorer's destination.  I find it particularly telling that, though it is well within what you might reasonably expect is Senswallahn territory, no one from Senaswallah ever has been seen there, and they make no attempts to keep anyone from entering.