Stanley says: [Footnote: "Sinai and Palestine," Lond. 1856, p.150.] "The moment that the religion of Palestine fell into the hands of Europeans, it is hardly too much to say that as far as sacred traditions are concerned, it became 'a religion of caves,' of those very caves which in earlier times had been unhallowed by any religious influence whatever. Wherever a sacred association had to be fixed, a cave was immediately selected or found as its home. First in antiquity is the grotto of Bethlehem, already in the second century regarded by popular belief as the scene of the Nativity. Next comes the grotto on Mount Olivet, selected as the scene of our Lord's last conversation before the Ascension. These two caves, Eusebius emphatically asserts, were the first seats of the worship established by the Empress Helena, to which was shortly afterwards added a third--the sacred cave of the Sepulchre. To these were rapidly added the cave of the Invention of the Cross, the cave of the Annunciation at Nazareth, the cave of the Agony at Gethsemane, the cave of the Baptism in the Wilderness of S. John, the cave of the Shepherds of Bethlehem. And then again, partly perhaps the cause, partly the effect of the consecration of grottoes, began the caves of the hermits. There were the cave of S. Pelagia on Mount Olivet, the caves of S. Jerome, S. Paula, and S. Eustochium at Bethlehem, the cave of S. Saba in the ravine of Kedron, the remarkable cells hewn or found in the precipices of the Quarrantania or Mount of the Temptation above Jericho. In some few instances this selection of grottoes would coincide with the events thus intended to be perpetuated, as for example, the hiding-place of the prophets on Carmel, and the sepulchres of the patriarchs and of Our Lord. But in most instances the choice is made without the sanction, in some instances in defiance of, the sacred narrative." It is questionable whether Dean Stanley is right in attributing the identification of caves with sacred sites to Europeans, it is probable enough that the local Christians had already fixed upon some if not all of them. After the pilgrims or the Crusaders had come in their thousands and visited the holy sites, they returned to their native lands deeply impressed with the association of caves with everything that was held sacred, and this, added to the dormant sense of reverence for places underground consecrated to holy purposes that had come to them from their parents, must have tended to the multiplication of subterranean churches.