He could easily imagine that he had unconsciously stumbled into the playhouse of Neptune's rollicking subjects.

The water formed a great pool surrounded by an amphitheatre of towering crags of most fantastic shapes, which reached far up toward the sky, there being no roof to its vast extent.

The waves beat in from the sea; but as no opening was visible, a subterranean passage surely formed the entrance.

Hundreds of grey ducks were startled and circled around him or flew back and forth to their nests as if fearful the intruder intended to do them damage.

These nests were built unlike those of any other duck he had ever seen, or in fact, those of any aquatic fowl, being hung in the cracks and crevices of the rocks precisely like the nests of the common barn swallow.