Catacomb of San Nicomede

Archaeological discoveries

From Antonio Bosio to the 20th century, several galleries have been found on the catacomb's presumed site, but none have been definitively identified as this catacomb:

Early in the 17th century Bosio mentions in his Roma sotterranea discovering a hypogeum to the right of Porta Pia, which he identified with this catacomb; he describes it in detail but no traces remain of it today

In the 19th century Giovanni Battista de Rossi discovered two hypogea of different sizes on land then belonging to marchese Patrizi (neither of them was the one discovered by Bosio; nothing now remains of the smaller one, whilst the larger one is under via dei Villini) and an above-ground apsidal monument (which he identified as a basilica dedicated to Nicomedes); he published his results, which convinced everyone the catacomb of Nicomedes had been found

In the 1920s, during the construction of the Ministry of Transport, more than thirty underground galleries over two levels, with other galleries discovered in following years, thus convincing archaeologists that de Rossi' identification was wrong; all of these structures have been lost under the above-ground buildings.