Passing by the Forum and the Colosseum, ruins piled upon ruins, he wandered past San Gregorio, where, in the garden, lie the remains of the Servian Porta Capena, by which St. Paul first entered Rome. The Via Appia, lined with vineyards and fruit-trees, shedding their blossoms on many an ancient tomb, led the solitary pilgrim from the memories of the present to the days, when the light of the early Christian Church burned like a flickering taper hidden low in Roman soil. The ground sweeping down on either side in gentle, but well-defined curves, led the vision over the hills of Rome and into her valleys. Beneath a cloudless, translucent sky the city was caught in bold shafts of crystal light, revealing her in so strong a relief that it seemed like a piece of exquisite sculpture. Fronting the Coelian, crowned with the temple church of San Stefano in Rotondo, fringed round with tall and graceful poplars, rose the immeasurable ruins of Caracalla's Baths, seeming more than ever the work of titans, as Tristan saw them, shrouded in deep shadows above the old churches of San Nereo and San Basilio, shining like white huts, a stone's throw from the mighty walls. Beyond, as a beacon of the Christian world in ages to come, on the site of the ancient Circus of Nero, arose the Basilica of Constantine, still in its pristine simplicity, ere the genius of Michel Angelo, Bramanté and Sangallo transformed it into the magnificence of the present St. Peter's. For miles around stretched the Aurelian walls, here fallen in low ruins, there still rising in their proud strength. Weathered to every shade of red, orange, and palest lemon, they still showed much of their ancient beauty near the closed Latin gate. High towers, arched galleries and battlements cast a broad band of shade upon a line of peach trees whose blossoms had opened out to the touch of the summer breeze. Beneath Tristan's feet, unknown to him, lay the sepulchral chambers of pagan patricians, and the winding passage tombs of the Scipios. Out of the sunshine of the vineyard Tristan's curiosity led him into the dusk of the Columbaria of Pomponius Hylas, full of stucco altar tombs. He descended into the lower chambers with arched corridors and vaulted roofs where, in the loculi, stood terra-cotta jars holding the ashes of the freedmen and musicians of Tiberius with their servants, even to their cook. Returning full of wonder to the golden light of day, Tristan retraced his steps once again over the Appian Way. Passing the ruined Circus of Maxentius, across smooth fields of grass, he saw the fortress tomb of Cæcilia Metella, set grandly upon the hill. It appeared to break through the sunshine, its marble surface of a soft cream color, looking more like the shrine of some immortal goddess of the Campagna than the tomb of a Roman matron.