Basilica of San Clemente, Rome

Few buildings show the layering of Rome as plainly as San Clemente. A staircase inside the church leads down through roughly two thousand years: from a twelfth-century basilica to the church that preceded it, and from there to Roman rooms of the first and second centuries, including a sanctuary of the god Mithras. The whole complex lies a short distance east of the Colosseum.

The deepest level holds foundations from before the Great Fire of AD 64, over which an industrial building — probably the imperial mint — and an apartment block were raised in the Flavian period. Around AD 200 a mithraeum was fitted into the courtyard of that block: a low vaulted room about 9.6 metres long, its far end trimmed with pumice to suggest a cave, with an altar showing Mithras killing the bull. In the fourth century the site was filled in and a Christian basilica dedicated to Pope Clement I was built above; St Jerome mentioned it in 392. That lower church keeps one of the largest groups of early medieval wall paintings in Rome. Among them, a scene from the legend of St Clement carries painted dialogue in which the pagan Sisinnius curses his servants in early vernacular Italian while the saint answers in Latin — one of the oldest written traces of the language.

The upper church was built in a single campaign under Cardinal Anastasius, roughly between 1099 and 1120. Its three naves stand on antique columns over a Cosmatesque inlaid floor; a twelfth-century choir enclosure reuses marble from the earlier church, and the apse mosaic, the Triumph of the Cross, is counted among the finest Roman mosaics of its century, with acanthus scrolls spreading around a crucifix. In the early eighteenth century Pope Clement XI had Carlo Stefano Fontana add the façade, completed in 1719, and the gilded coffered ceilings. Irish Dominicans have held the church since 1667; their prior Joseph Mullooly began excavating the lower levels in the 1860s. A side chapel keeps the tomb of St Cyril, who with his brother Methodius created the Glagolitic alphabet for the Slavs.

Getting there

San Clemente stands in central Rome, about 1 km from the historic centre and a few hundred metres east of the Colosseum; the nearest metro stop is Colosseo on Line B. The nearest airport is Rome Ciampino (CIA), about 13 km away; Rome's main international airport, Fiumicino (FCO), lies on the coast to the west.