Mr. P. H. Gosse, in his interesting work, Tenby: a Sea-side Holiday, 1856, p. 80, informs us that” the people talk a good deal of a curious cavern called Hoyle’s Mouth, about which they have some strange notions. It opens at the end of a long lime-stone hill, or range of hills, about a mile inland; and the popular legend is, that it is the termination of a natural subterranean chasm which communicates with the great cave called, the Hogan, under Pembroke Castle, some eight miles distant.
It was once traversed, they say, by a dog, which, entering at one end, emerged from the other, with all his hair rubbed off! A gentleman is said to have penetrated to a considerable distance, and found ’ fine rooms.’ But the vulgar are very averse to exploring even its mouth, on the ostensible ground that a boar,’ a wild pig,’ dwells there; I fear, however, that there are more unsubstantial terrors in the case. I walked out to look at it; and if I found no dragons, nor giants, nor pigs, I enjoyed a most delightful rural walk.”
From Notes and Queries, October 12, 1861.