White fleshy blooms are crushing the cave, cupping hands around it's centre like a throat.
The rock is cracked and bulging like a paving slab broken from below. Touching the foamy mass makes it tremble and close another radial foot. When the fungal valve seals the cave it will bleed liquid stone. The fungal overmind has a very important reason for doing this which you should immediately invent and keep secret.
A chain of huge, linked overhangs in the distant ceiling of a cave.
A chain of broken half-tubes in a high roof. Possibly the relics of a lava tube or collapsed river bed. The tube chunks must be leapt between mario-style. The linier arrangement leads to a chimney or crack in the cave wall that yakes you down, then back across the floor below in the opposite direction. The ground floor is a new cave type, roll again.
An enclosed space filled with light.
A high ceiling and utterly clear, smooth walls that rise thirty feet or more then bow out invisibly like a muffin top. The roof, far above, is bright. Either semi-precious gems, or veins of burning tar, reflective obsidian shards or prsim'd crystals. High, unreachable and cascading light. It feels like entering an outdoor space. There is no cover here of any kind and no-where to hide.
A cave shaped from below by deep-earth chemistry.
This cave has nothing to do with normal formations. It shape is wrong, like a tear made of tears. An entry to a stranger level of the world. One not shaped by comprehensible life. Sulphur rots the rock. Walls are tooth-torn gashes, scars of invisible claws, floor a ripple of rips like torn chicken. Rivers entering will change after this point.
GYPSUM FLOWER FIELD
Crammed with impossibly beautiful bright stone flowers.
Blooms in elemental chemical shades. Sharp arsenic yellow, cerulian blue, heart-blood-bright red. A blurring blaze of unexpected colour. Wild animals (not monsters) will be surprisingly calm here. Narrow winding paths lead through. Smashed flowers are razor sharp and sometimes poisonous. Unusual ones can be valuable to sighted buyers.