Mysterium Fidei is a later 20th century convent chapel at Viale Tito Livio 24 in the Trionfale quarter. (The convent has two entrances, and the one nearer the chapel is at Via Fedro 40.)
The dedication is unique for Rome, to the Mystery of Faith.
The Suore Missionarie Pie Madri della Nigrizia were founded by St Daniel Comboni at Verona in 1872 for missionary work overseas, especially in Africa. The Italian name literally translates as "Missionary Sisters, Pious Mothers of Nigrizia (i.e. black Africa), but for very obvious reasons they are known in English as the Comboni Missionary Sisters.
The congregation built a new Generalate or headquarters in Rome in 1970, and the chapel by Mario Paniconi was opened in 1971.
The chapel as a cultic centre is dependent on the parish of Santa Paola Romana , but it is private and no public liturgical events occur here.
The edifice has the plan of a fourteen-sided irregular but symmetrical polygon (a tetrakaidecagon), based on a regular octagon. The front and back sids of the octagon are kept, but the other six sides are each given an obtuse internal angle.
The front and the near diagonal sides of the base-octagon are abutted by a single-storey range of the convent complex. The other sides have low walls in red brick, with window strips below the substantially overhanging roof eaves.
The roof has steep triangular pitches corresponding to the sides of the tetrakaidecagon. These meet at a lantern, over which is a spirelet or flèche consisting of four concrete vanes meeting at a point. The roof is covered in a dark grey composition.