Cave of Whispers

Welcome to a new scale on the great indoors.
This is the largest underground cave system yet to be discovered. Here, the inner space is so gigantic that sound waves are warped inside of it. A pin drop on one side can reverberate off of all of the walls to create a never ending echo on the other. Legend has it that once, somewhere in the middle of the cave, the heathen gods dropped a boulder into the middle of the cave, trying to kill everything inside, but the native's high priest whispered a chant to stop the oncoming tide. Just like the wave, any noise that enters there apparently never leaves.....
Wait, what was that about the natives?

Rendered in Truespace 3.2, edited in Photoshop.