The church located at the bottom of the Palatino, has an unusual but very gracious round structure. Already existing at the end of C.VI, it was restored numerous times nonetheless keeping the original imprint. 

It is preceded by a semi-circular building designed by Carlo Fontana in 1705, which is accessible via two stairways that, starting at the ground level, flow down on two sides thus creating a cute framework to the little square. Extraordinary beauty can also be attributed to the dome, dated 1454. 

The interior is enriched by the splendid mosaics from C.VI. The ceremony for the Venerdì Santo, which is held in the church by the hand of the Confraternita dei "Sacconi rossi" that are here located, is also very typical and characteristic.