Catacombs of Commodilla

The earliest level is the most interesting in archaeological terms, re-using an ancient pozzolana quarry and housing Felix and Adauctus' tombs in a small underground basilica (which contained the notable Commodilla catacomb inscription).

Along with Felix and Adauctus, the complex also traditionally housed the remains of: A unique feature of the complex and of the catacomb of Saint Thecla compared to other catacombs in Rome is the presence of burials 'a pozzo' (literally, in the well), meaning deep ditches containing up to 20 burial niches along the sides, placed one on top of the other.

The Commodilla complex is also marked by poor iconography, architecture and epigraphy - its marble inscriptions often include spelling errors and 'cubiculi' and arcosolium tombs are rare.

Under Pope John I (523-526) it was re-excavated, adapting part of the former pozzolana quarry on the second level, which was closed and enlarged to make room for the martyrs' cult.

Other features are: At the centre of the complex is also the so-called 'cubiculum of Leo', a Roman annona official (second half of the 4th century), who commissioned it for him and his family.