Sacello di San Zenone, Ninth-century chapel in Basilica of Santa Prassede, Rome, Italy.

The Sacello di San Zenone is a small chapel set within the Basilica of Santa Prassede in Rome, with every wall and ceiling surface covered in mosaics. The golden backgrounds and religious figures wrap around the entire interior without a single bare surface.

Pope Paschal I had the chapel built in the early 9th century as a burial place for his mother. It was set into the existing basilica and has kept most of its original decoration since then.

The chapel's name comes from Saint Zeno, a Roman martyr whose remains Paschal I moved here from the Catacombs of Praetextatus. On the left wall, Agnes, Pudenziana and Praxedis hold their martyrdom crowns with veiled hands, and Theodora, the pope's mother, appears with a square halo, a sign she was still alive when the mosaic was made.

The space is very small, so it helps to enter slowly and give your eyes time to adjust to the light inside. A coin activates the lighting system, which lets you see the mosaics at their brightest.

The relics of Saint Zeno himself lie in this chapel, brought here from the Catacombs of Praetextatus at the time of Paschal I. In the mosaic of the left niche, his patroness Teodora appears with a square halo, a sign that she was still alive when the work was made.