The church of Santa Maria in Cosmedin was founded in C.VII, on the place where once was the Ara Maxima Erculi (a big hall with a porch from Flavius’ time, from which one only has various columns incorporated in the building, the antique food market of the city), dedicated to the cult of the Greek semi-god. 

During C.VIII the church was destined to the byzantine monks who had settled down by the Tiber, upon escaping the Oriental iconoclasts’ persecutions. Due to the decorations that were brought, the building also got the name "Cosmedin" which can be translated into Gree in “decoration”. 

Restored and remodeled numerous times along centuries, the church’s interior shows some evocative decorative elements from C.VIII and XI, such as the Women’s Gallery and the "Schola Cantorum", while the exterior embodies the bell-tower in seven floors of mullioned and three-mullioned windows, one of the nicest ones in town showing a Romanesque style. 

The interior is evocative and severe, radically recovered in its original shapes during C.VIII. It has three naves divided up by four pilasters and eighteen antique columns. The porch, added during C.XII, hosts the famous Bocca della Verità, very cherished in popular tradition for the popular belief that the mouth could bite the hand of whoever would not express the truth.