These are the details: Before us was an immense cavern, circular in shape, with a diameter of some half a mile.

Was she in some immense upper cavern, its Ice roof too remote to see?

Several of the bulkheads had been cut away and it seemed as though he were standing in an immense cavern.

I looked out upon an immense cavern, cut from the living rock by the hands of men dust now for thousands of years.

The sea had its own huge, hollow noises, like an immense, empty cavern.

We were in an immense cavern, the size of a cathedral.

Troi moved toward the light, and turning the corner, found herself looking into an immense natural cavern.

The light came from the walls of the immense cavern.

Finally, he reached a lift tube that would take him out into the immense cavern.

The doors opened at last, and they stepped into an immense circular cavern three hundred feet in diameter.