Several of the islands are hollow, with enormous caves.
They all made their way down the tunnel that led past the hidden store of valuables, and came out into the enormous cave.
In a moment all six were clawing their way back into the enormous cave from which they had just escaped.
The mouth of the enormous cave was also that of the underground river.
After a while, the tunnel we were following jogged sharply left, then right again, and suddenly it opened out into an enormous cave.
He found himself in an enormous dimly lit cave.
They looked out into a cave so enormous that it seemed almost as big as the world outside.
It was strange to see it there, running through an enormous cave.
The two children looked in; it seemed an enormous cave in there, impossibly dark.
There were no windows, so it felt as if we were in an enormous, dark cave.