The Basilica of St. Mary of the Altar of Heaven (Latin: Basilica Sanctae Mariae de Ara coeli in Capitolio, Italian: Basilica di Santa Maria in Ara coeli al Campidoglio) is a titular basilica in Rome, located on the highest summit of the Campidoglio. It is still the designated Church of the city council of Rome, which uses the ancient title of Senatus Populusque Romanus. The present Cardinal Priest of the Titulus Sancta Mariae de Aracoeli is Salvatore De Giorgi.
The original unfinished façade has lost the mosaics and subsequent frescoes that originally decorated it, save a mosaic in the tympanum of the main door, one of three doors that are later additions. The Gothic window is the main detail that tourists can see from the bottom of the stairs, but it is the sole truly Gothic detail of the church.
The church is built as a nave and two aisles that are divided by Roman columns, all different, taken from diverse antique monuments. Among its numerous treasures are Pinturicchio's 15th-century frescoes depicting the life of Saint Bernardino of Siena in the Bufalini Chapel, the first chapel on the right. Other features are the wooden ceiling, the inlaid cosmatesque floor, a Transfiguration painted on wood by Girolamo Siciolante da Sermoneta, the tombstone of Giovanni Crivelli by Donatello, the tomb of Cecchino dei Bracci, designed by his friend Michelangelo, and works by other artists like Pietro Cavallini (of his frescoes only one survives), Benozzo Gozzoli and Giulio Romano. It houses also a Madonna and a sepulchral monument by Arnolfo di Cambio in the transept.