The Atlantic lay still as a pool in a deep cavern.
But only the moon looked in at the hollow dark, the deep caverns.
But suddenly they emerged on a natural balcony, high in the side of a vast deep cavern.
Also they took small prey animals who could live in these deep caverns.
Perhaps it was written by some early explorer who somehow got into these deep caverns.
They are normally only encountered in deep, dark caverns, far beneath the earth.
However, a small distance from the site, an unusually deep cavern was discovered.
In some places you could see down through into deep caverns.
The river can sometimes run through deep wide underground caverns.
Dark, as if it dwelled in the deep caverns of the mind.