No sign of human presence appeared, and I ventured to stand upright.

The cavern possessed a wide opening, with a broad platform of rock extending well out beyond the face of the cliff.

Along the edge I could observe the rather dim outlines of an immense altar, built of detached stones, rising to a considerable height, and partially blocking the entrance.

From below it might serve to conceal the mouth of the cave.

This obstruction shut off much of the moon's light, rendering the interior intensely dark.