A few meters beneath ground, where temperature is constant but humidity is high and food is scarce, is a placed filled with unexpectedly flourishing biodiversity. Mostly hidden within an inaccessible labyrinth of small cracks and voids in limestone rocks, this habitat is invisible and unknown to most. The karst caves, being a very small fraction of these voids large enough for a human to enter, provide a rare opportunity to study these highly specialized forms of life.
In a world without light, eyes and colors become useless so the underground life here has enhanced other senses to overcome this deficit. This high specialization to the underground environment limits these species to very tiny regions (confined by rivers), creating an incredible high level of endemism ― most of these species are found underground in only a single mountain or sometimes in a single cave.