Farther on we came off vast masses of rock piled one upon another.  The two yachts having hove-to, we pulled on shore, and, under the guidance of the pilot, managed to land; when, climbing up some distance, we reached a cone, from the bottom of which we could hear the sea roaring fearfully.  We then arrived lower down at a small opening, when a guide, who had joined us, lighted some candles, that we might find our way into a celebrated cavern, called "Piper's Hole."  For some distance we had to crawl along on our hands and knees.  At length we reached a narrow but high vault; this we followed until we arrived at the head of a ladder. "You will find a boat at the bottom, gentlemen," said the guide.