Basilica Anonima della Via Ardeatina is a ruined palaeochristian basilica just east of the Via Ardeatina, south of the junction with Via Luigi Capucci. However, it is accessed by a rough driveway off the Via Appia Antica (look for the cypresses on the right, south of Domine Quo Vadis).
There is no documented history before the excavation in 1991, when a funerary complex including the basilica, several large mausolea and two levels of catacombs were archaeologically excavated. This is the first time that a major palaeochristian Roman basilica on a site undisturbed by later buildings has been excavated with full professional standards. The basilica itself was circiform, meaning that it was on the plan of an elongated arch with a semi-circular far end and an ambulatory. This resembles an ancient Roman circus or race-track, such as the Circus Maximus, and this is the sixth paleochristian basilica discovered in Rome on this plan. The dimensions are 66 by 28 metres.
The excavation revealed that the complex had been built over a small pre-existing pagan cemetery, and two ancient structures which the excavators called the "Big Villa" and the "Little Villa".
The Christian complex is dateable on stylistic grounds to the Constantinian period in the early 4th century. It was intensively used for funerary purposes through the 5th century, but only sporadically in the 6th and 7th centuries. It seems to have been abandoned about the year 700.
Very unfortunately, no inscription was discovered which could identify the church. The supervisor of the excavation considered that the most likely documented candidate was a basilica dedicated to Pope Mark, which is known to have been somewhere in the area and which was built in 336. However there are other possible churches which this might have been, especially one dedicated to Pope Soter, and the uncertainty has led to the label "anonymous".
The catacombs underneath this complex are quite extensive, at two levels.
Nestori, Aldo: La Basilica Anonima della Via Ardeatina, Vatican 1990.
This is a short summary of the archaeological findings, of 125pp.