Chromatic Cavern

The gray limestone walls of this long cave are encrusted with mineral coatings in a variety of colors: orange, red, brown, black, and yellow. Several areas in the cavern system are crowded with formations - stalactites, stalagmites, columns, and draperies. Most of these are pure white, glowing translucently in a visitor's light. Some are a dark opaque red, or have red roots starkly contrasting with their white newer growth.

Dimensions Several main passages run linearly for hundreds of yards/meters, and the total length of passages is about a mile (1.6 kilometers). Many passage floors are less than a yard/meter) wide, with walls sloping back to allow somewhat more room two yards/meters above floor level. These passages are a few yards/meters high. A few rooms in the cave are much wider, ten or twenty yards/meters across, but have low ceilings only about three feet (one meter) high.

Key Details

The cave mainly consists of a few long, very straight passages intersecting each other at odd angles. Its cave map would look like scattered matchsticks. These long passages are quite narrow, especially at foot level, requiring characters to proceed single-file.
In some spots there are short branch passages connecting to other nearby main passages, or ending in plugs of dried cave mud. The corners leading into these branches are very sharp, making a side passage difficult to notice until a person is right next to it. A few inches of water covers the floor in some side passages.

The narrow-floored passages are widest about at a person's shoulder level, reducing feelings of restriction, providing space to swing arms, and enhancing the lengths of down-passage views for groups walking single file.
Yellow and orange iron oxides, black manganese oxide and carbon, white calcite coat the walls. They seeped down with water from the rocks and soil above. Dark red stalactites and draperies are very rare cave features, made of pure natural rust (iron oxide) formed in an earlier era than the white stalactites.
The cave sits within a low bedrock ridge that rises gently above a broad, deep-soiled plain and nearby hills. Its natural entrances are in sinkhole depressions on the wooded slopes.
Many of the smallest-size white stalactites are soda straws, thin and hollow-centered. Unlike the other stalactites, stalagmites, and columns, these are fragile and easy to break off. Water drops hang at their bottom tips, depositing more calcite there to aid their growth, A few of these tiny formations are seldom-seen helectites (at right), seemingly ignoring the pull of gravity by growing sideways rather than strictly downward.
In some sections of narrow passage the ceilings are high-reaching crevices just inches/centimeters wide, marking the straight lines of bedrock fractures. In other sections the ceilings are very irregular in height, or are perforated by multiple holes revealing larger empty space just above.
Low-toned sounds (low voices, bass musical notes) reverberate strongly in the narrow passages, carrying great distance. Higher tones (treble notes, whispers) do not carry very far.

Some of the wall and ceiling mineral deposits are knobby or are composed of close-set drapery lines. These present rough edges to brush against, and small recesses where light cannot easily reach.
The low-ceilinged, wide rooms have floors of dried cave mud. In areas where there are stalactites, many of these have grown to reach the floor and form solid columns, making a character's crawling path more difficult. Stalagmites and broader sheets of rough calcite coat the mud in some floor areas. Previous owners dug out the mud in a few locations, making two-level sections of passage separated by a calcite rock floor.

Story Elements

The walls of this cave, hollowed out over tens of thousands of years, could have many stories to whisper.
Water dripping through the cave altered its trace chemical composition over its long existence, producing the different-colored formations. What happened on the ground above, to cause this change? This is an actual remaining mystery in natural history of the cave; but a storyteller might offer some fantastic interpretations related to their narrative. For example, maybe the orange and gold colors in this cave bear witness to a great battle occurring in the autumn long ago. So much blood was spilled that it dripped from the tree branches, symbolized now in the rust stalactites. Then winter suddenly took hold, covering all with snow and pure white icicles which persisted for months as the land mourned.
On a passage ceiling, a crucial map or image might be hidden among the lines and patches of natural mineral deposits. An odd-shaped helectite might be a memorable landmark, with a shape that gives characters directions in their quest.
A local person familiar with the cavern will have advantage in navigating it, knowing locations of side passages ahead but out of sight down the long avenues. They will know the best ways to avoid monsters, difficult floor areas, or other hazards. They'll know the specific locations of things that can be mined, harvested, or hunted. They may be able to move safely with no light.
Narrow floors of most passages in this cave not only dictate single-file movement, but make it difficult for group members to squeeze past each other while keeping their footing.
Characters can move throughout this array of passages without need to climb up or down; the passage floors are quite level. There are rare spots where a side passage ends in a pit leading further down into the bedrock. This opens the possibility of further exploration into spaces with deep water or other challenges. A pit might also be an emergency hiding spot, or source of a new threat rising into the main passages. Such a spot could hide some treasure, a reward for a diligent searcher.

Other hiding places for characters aren't abundant, but one a refuge be found in a small side passage partly filled with mud, or perched above the solid calcite sheet of an old floor level.
A ceiling crevice could be the nesting place of small flying creatures, ready to fill the air of the passage when disturbed.
Low-toned voices or drums will reverberate throughout the whole cave system, because those types of sounds carry far here. This effect could enhance the effectiveness of an alarm. It would also make it harder to discern the direction and distance of the sound's origin. A high-pitched voice or tinkling sound would only be heard on close approach to the source.
A society could hold rite of passage tests here - proving maturity, cementing partnerships, testing loyalty, settling disputes.
What would it be like if a society (post-apocalyptic? high-tech?) did not honor the natural cave system, but used it for their own purposes? There's water here, hiding places, and lots of space - how might someone use this environment? A mushroom farm? A hidden community? A sculptors' school (carving the stalactites, flowstone, etc.)? A toxic workshop?

Reference Location

Ohio Caverns, in west-central Ohio. This commercially operated cave is open throughout the year, excepting some holidays. Most of the areas featured in this article can be seen on the Winter Tour or the summer Natural Wonders tour.