Basilica of St. Mary of the Angels

The Basilica of St. Mary of the Angels and of the Martyrs is a basilica and titular church in Rome, Italy, built inside the ruined frigidarium of the Roman Baths of Diocletian in the Piazza della Repubblica.

It was constructed in the 16th century following an original design by Michelangelo Buonarroti. Other architects and artists added to the church over the following centuries. During the Kingdom of Italy, the church was used for religious state functions.

Source: Wikipedia