This was a rural chapel of the sort that served the Campagna countryside before the suburban expansion of the city. Like several others like it, it was built in a century when major landowners began to take notice of the pastoral needs of farmworkers.
The chapel was attached to a farmstead on the old road of the Via Portuense, known as the Casa Fantini (literally "Jockey House" in English).
It has been deconsecrated for a long time, certainly since the local parish church of San Girolamo a Corviale was established in 1960.
At present the edifice functions as a bar, the Bar Roca, but the fabric is neglected and not in good condition.
The Casa was rebuilt in the 18th century, and is still a dignified-looking edifice set back from the street. The chapel attaches to the left hand end of this, and has its frontage on the road. The two buildings thus form an L. The left hand side of the chapel is on the Via della Casetta Mattei.
The plan is rectangular, formed of two separate square units as nave and sanctuary. These have separate pitched and tiled roofs, the nave one being behind a parapet. The sanctuary roof is higher, and has a projecting cornice instead. There is a semi-circular apse, and on the left side of this is attached a tiny triangular sacristy.
The sanctuary frontage has a little round window where the ridge-line of the nave roof meets it.
The fabric is in random tufo rubble, originally rendered although much of this has fallen off. The nave parapet is in brick, and brick is also visible in the fabric of the sanctuary.
The frontage has a higher parapet than the nave walls, and below this there is an outline of a triangular pediment in the rotting stucco over the single entrance.
Around the left hand side, you can see that the nave was added on to the sanctuary, which must have been the entire original chapel. Presumably it was extended in the 18th century rebuilding of the farmstead. The nave had a single rectangular window, now blocked, and the sanctuary two at different levels -one of these is also mostly blocked. On the roofline of the sanctuary you can see the remains of a little bell-cote.