In my thoughts of the shore， one place stands apart for its revelation of exquisite beauty. It is a pool hidden within a cave that one can visit only rarely and briefly when the lowest of the year' s low tides fall below it， and perhaps from that very fact it acquires some of its special beauty. Choosing such a tide， I hoped for a glimpse of the pool. The ebb was to fall early in the morning. I knew that if the wind held from the northwest and no interfering swell ran in from a distant storm the level of the sea should drop below the entrance to the pool. There had been sudden ominous showers in the night， with rain like handfuls of gravel flung on the roof. When I looked out into the early morning the sky was full of a gray dawn light but the sun had not yet risen. Water and air were pallid. Across the bay the moon was a luminous disc in the western sky， suspended above the dim line of distant shore the full August moon， drawing the tide to the low， low levels of the threshold of the alien sea world. As I watched， a gull flew by， above the spruces. Its breast was rosy with the light of the unrisen sun. The day was， after all， to be fair.
Later， as I stood above the tide near the entrance to the pool， the promise of that rosy light was sustained. From the base of the steep wall of rock on which I stood， a moss-covered ledge jutted seaward into deep water. In the surge at the rim of the ledge the dark fronds of oarweeds swayed smooth and gleaming as leather. The projecting ledge was the path to the small hidden cave and its pool. Occasionally a swell， stronger than the rest， rolled smoothly over the rim and broke in foam against the cliff. But the intervals between such swells were long enough to admit me to the ledge and long enough for a glimpse of that fairy pool， so seldom and so briefly exposed.
And so I knelt on the wet carpet of sea moss and looked back into the dark cavern that held the pool in a shallow basin. The floor of the cave was only a few inches below the roof， and a mirror had been created in which all that grew on the ceiling was reflected in the still water below.