The New Gulliver by Barry Pain

The side of the brown sandstone cliff was perforated like a gigantic rabbit warren. I judged the cliffs to be natural in character, but in the labyrinth of passages and rooms upon which one first entered, much artificial work had been done. In places columns of brick upheld the roof, and the walls had been trimmed and levelled by a tool. I guessed -- for it was a point upon which Dream could tell me nothing -- that the lords of Thule had at one time some intention of making use of these natural excavations, and that they had been frightened from their task by the absurd superstition which Dream had recounted to me. I could not believe in the marvellous amphibious monster that had come out of the sea, and for fifty years or more had lived in the heart of these cliffs.

I told Dream of my doubts, but she was not to be shaken. The track of the animal when it went in had been clearly visible, and no track had been found to show that it had gone out again.