Geography: This unusual area is the product of an ancient
earthquake-probably the same one that adjusted the water
table and dried up the nearby caves. Originally, the entire region
lay upon the surface. A tall, thick forest flourished under the
steady rays of the sun, and many small villages nestled among
the trees.

Then faults deep within the earth were split asunder, and the
land fell. Trees, buildings, animals, and humans were tossed into
the gaping holes that opened within the earth, and massive walls
of rock toppled inward, crushing most of the unfortunate victims
of the quake.

In a few places, however, the massive faces of rock wedged
against each other, leaving vast hollow spaces below them. In
those spaces humans and animals miraculously survived.
More than a dozen huge chambers make up this region. The
nature of the faulting has resulted in areas of 1,000 to 4,000 feet
wide and 3d6 miles long. Unlike most of the realms of Deepearth,
the caverns of the sunken swamp are lined with dirt. The timber
and living plants have long since rotted, creating a damp and
spongy surface. Many small streams trickle through the cracks in
the fault above, dropping a fine mist throughout the area. Slimy
mosses and fungi line the rock faces and glow enough to provide
a dim light source.

The separate caverns of the sunken swamp were originally isolated
from each other by vast, choking mounds of dirt and tree
trunks. Throughout the centuries, however, the survivors of the
quake and their descendants have worked hard to link the
caverns. Now, wide, straight tunnels slice through the mounds of
earth, linking each cavern to at least two others. The tunnels
have been shored with ancient timbers from massive trees,
which were thoroughly soaked in oil to delay their inevitable rot.

Denizens: The humans who survived the earthquake continued
to live and reproduce in their new, dark environment. As the
generations passed, however, memories of life on the surface
faded. Now none of them can recall the origins of their land,
although legends tell of a great, cataclysmic punishment meted
out by vengeful gods. Those who survived, legend has it, were
the chosen few selected to purify the race and start over again.
In fact, however, the humans of the sunken swamp have
degenerated with each successive generation. First cleanliness,
then education, then clothing were abandoned by these pathetic
descendants. Now their state might best be described as subsavage.
Cannibalism is not unheard of among these folk. They
have splintered into several small groups, each certain that they
alone are the race chosen to lead the rest.

Each of the large caverns in the area hosts a human population
ranging from 50-100 dirty, scraggly people. Their speech has
become very primitive-a means of conveying emotion rather
than information. They are suspicious and distrustful of all strangers,
but are not automatically unfriendly. In fact, these people
are very curious about the rest of the world, and if visitors arrive
peacefully, they are usually invited to stay for a few weeks. The
natives display great curiosity and interest in their visitors during
this period. After this time of study is over, the visitors are eaten.
Occasionally, the population of the sunken swamp is swept up
in a brief period of savage warfare. No group accepts any allies,
so the result is a massive and deadly free-for-all, with each group
treating all other groups as mortal enemies. After a few days of
slaughter and bloodshed, the survivors lose interest in the conflict,
and a great reconciliation council is held. The high point of
the council is the devouring of the war casualties.

Other creatures also live on the spongy loam of the sunken
swamp. Most varieties of underground scavengers are present.
A few shambling mounds have found comfortable lairs here.
Snakes and spiders of all types enjoy this environment, as do
monstrous toads and frogs. Plentiful growths of fungi provide key
food elements for humans and some of the other inhabitants.

Resources: The steady misting rain from the surface creates
a region of high humidity. In many places, water showers down
on characters. The air is muggy and thick, smelling heavily of
decay and death. Oxygen, however, is fairly plentiful, as the air
seems to circulate through the same vents that give access to the
water.

The spongy earth of the sunken swamp is easy to dig, but not
solid enough to hold its shape. Thus, it is not used to create burrows
or above-ground structures. In a few places, the remains of
the forest have stayed dry and created a substance similar to
peat, which burns for a long time when ignited. It creates a very
smoky and smelly fire, however, so it is not commonly used by the
residents of the sunken swamp.

Unique Features: A few structures from the surface survived
the quake relatively intact and have come to be regarded as
sacred places by the folk of the sunken swamp. The most prominent
of these is a vast temple lying in the center of the largest
chamber. This temple is surrounded by shattered stone columns
and the rubble of a large community. The temple itself is a squarish
structure made of solid blocks of stone. The roof collapsed
when the building fell, but all of the walls remain. The inside of the
temple includes a large, central courtyard and a number of
smaller rooms around the periphery of the building. It contains a
number of gold, silver, and platinum relics of ancient religious
value-relics that the current residents have no use for. In fact,
the temple is one of the safest places in the sunken swamp since
the human inhabitants hardly ever venture there.

A few other stone structures, all without roofs, lie scattered
among the caverns of the sunken swamp. These were once
sturdy and solid structures, such as vaults, armories, and
prisons. In one cave, an armory still contains an assortment of
corroded normal weapons. The weapons could be made quite
useful with a little sharpening, but the residents do not employ
them since they have been declared sacred.

The smallest of the caverns in the sunken swamp is unique in
that it receives no natural water from above. Consequently, the
trees and wooden rubble from buildings did not rot. Instead, a
rapid form of petrification set in. This wood looks virtually the
same as it did when it landed after the earthquake. The wood has
grown hard, almost stone-like, and cannot be burned.