Carlsbad Caverns #1
This other page has most of the tour displays
explaning these specific cave formations.
Colored lights are not used in the cave so that the natural colors are more evident. A long time ago, (40 years), the cave was much brighter. The park service found that the bright lights were damaging to the formations so less lights are the case today. Since a flash only works to about 5-7 feet, most pictures are quite dark. The pictures had to be taken with a flash so that it would not be fuzzy with an exposure so long. they are still dark because most formations are more than 10 feet away so the pictures had to be digitally lightened.
Most of the cave does not seem to be active at the present time. There has been a drought for a long time and the cave is literally drying up. The pictures that look slick or wet are the active parts of the cave.