Now, the first observation that I made, standing upon the verandah of the house, was one concerning the sea and my situation regarding it. I observed immediately that the harbour of Villa do Porto lay hidden from my view by the Eastern cliff of the valley. The Atlantic showed me but two patches of blue-green water, one almost to the south-west, and a second, of greater extent, to the north. Except for these glimpses of the ocean, I had no view of the world without the valley—not so much as that of a roof or spire or even of the smoke of a human habitation. Whoever had chosen this site for his châlet of the hills had chosen it where man could not pry upon him nor even ships at sea become acquainted with his movements. The fact was so very evident that I accepted it at once, and turned immediately to an examination of the grounds themselves. In extent, perhaps, a matter of five acres, my early opinion of their security was in no way altered by a closer inspection of them. They were, I saw, girt about everywhere by the sheer walls of monstrous cliffs; and as though to add to the suggestion of terror, I discovered that they were defended in their weakness by a rushing torrent of boiling water, foaming upwards from some deep, natural pool below, and thence rushing in a very cataract close to the wall of the mountain at the one spot where a clever mountaineer might have climbed the _arrête_ of the precipice and so broken the prison. This coincidence hardly presented its true meaning to me at the first glance. I came to understand it later, as you shall see. Walls of rock everywhere; no visible gate; no path or road, no crevice or gully by which a man might enter this almost fabulous valley from without! To this conclusion I came at the end of my first tour of the grounds. No prison had ever been contrived so cunningly; no human retreat made more inaccessible. As they had carried me through a tunnel of the mountain last night, so I knew that the owner of the châlet came and had returned, and that, until I found the gate of that cavern and my wits unlocked it, I was as surely hidden from the knowledge of men as though the doors of the Schlussenburg had closed upon me.