The Via Ardeatina lies a little distance to the right of the Via Appia, from which it branches off close to the Church of “Domine quo vadis,” the traditional scene of the appearance of the Lord to S. Peter. In the immediate neighbourhood of the Via Ardeatina and the Via Appia lie, roughly speaking scarcely two miles from the city, the wonderful group of cemeteries generally known under the names of Domitilla and Callistus. These include the Cemetery of Lucina--really an area of Callistus, the Cemeteries of SS. Marcus and Balbinus and also that of S. Soteris. This enormous network of subterranean corridors, chambers, and chapels are all more or less united by passages and corridors (though this is not quite certain); but much is as yet unexplored, and the lines of demarcation between the several Catacombs uncertain. Recent careful investigations of De Rossi, Armellini, Marucchi, and others less known have, however, led to the discovery of certain great and notable historic crypts, centres round which the network of corridors are grouped. These identifications have thrown a flood of light upon the very early history of the numerous and influential Roman congregations; much that was supposed to be purely legendary and fabulous has passed, as we have observed, into the domain of real history. Very briefly we will touch on a few of the more remarkable “finds.” _Cemetery of Domitilla._--The famous group of Catacombs known under this general title--perhaps with the sole exception of the Cemetery of S. Priscilla and the Cemetery of S. Callistus, hereafter to be described, is the vastest of all the Catacombs; and with the exceptions just alluded to, in some of its areas, the oldest in point of date. Much of this great cemetery dates from the time of men who knew the Apostles Peter and Paul. Its _grandeur_.--It was the burying-place of certain Christian members of the imperial house of Vespasian, Titus, and Domitian in the days of their power, and it tells us with no uncertain voice that in the ranks of the Christian congregation of Rome in the very first days were members drawn from the highest ranks of the proudest aristocracy of the world, and who did not shrink from sharing the same seats in the Christian prayer homes with the slave and the little trader. Writing of the Domitilla Cemetery in 1903, Marucchi does not hesitate to style it perhaps the most important of all the Catacombs; but, “alas!” he goes on to say, “it has been terribly ravaged by comparatively modern explorers.” These destructive explorations have sadly affected the importance which the Catacomb and its several divisions, or areas, would have possessed as a great monument of very early Christian history, had these recent excavations been carried out with due care and reverence.