Basilica of San Clemente

San Clemente makes Rome's vertical history unusually literal. The present basilica was built around 1100 above a fourth-century church. Beneath that lie first-century Roman buildings, including a house, industrial structure, and a sanctuary of Mithras. Descending through the excavations moves backward nearly a millennium while modern traffic continues just outside.

The upper church preserves a luminous 12th-century apse mosaic. A cross grows like a tree of life through curling acanthus vines filled with people, animals, and scenes of work. Its Cosmatesque floor and marble choir enclosure reinforce the medieval setting. The lower basilica contains important frescoes, including a story of Saint Clement and Sisinnius with an early example of vernacular Italian text written beside the figures.

Irish Dominicans have cared for the complex since 1677. In the 19th century, Father Joseph Mullooly led excavations that rediscovered the buried basilica and ancient levels. Archaeological work continues, and damp underground passages require careful conservation. The upper basilica is undergoing major restoration with scaffolding expected through mid-2027, though the excavations remain the main reason to visit. Book online, bring a light layer for the cooler levels, and listen near the bottom for running water beneath the city.

Did you know

• A Mithraic sanctuary is the answer to one of the most useful details to remember on site.
• Tree-of-life apse mosaic in the upper basilica.
• Early vernacular Italian words in a lower-church fresco.

Architecture and details

Begin with the building's plan and light before concentrating on individual artworks. The contrast between reused columns, later chapels and the main liturgical axis shows how Roman churches accumulated rather than replaced history. At Basilica of San Clemente, compare these broad choices with the specific materials, openings and proportions described on site.

What to look for

• Tree-of-life apse mosaic in the upper basilica.
• Early vernacular Italian words in a lower-church fresco.
• Mithraic altar in the deepest accessible level.
• Changes in masonry and floor height between the three main layers.

Today

Monday–Saturday 9:00 a.m.–12:30 p.m. and 2:00–6:00 p.m.; Sunday and holidays noon–6:00 p.m.; last entry 30 minutes before closing. Excavation booking is required. Shoulders and knees should be covered. The underground route has many stairs, low light, damp surfaces, and no wheelchair access. Upper-basilica scaffolding is expected through mid-2027. Hours, price, and restoration status checked 2026-10-07. Book online, bring a light layer for the cooler levels, and listen near the bottom for running water beneath the city.