Regina Coeli, Prison in Trastevere district, Rome, Italy.

Regina Coeli is a prison on via della Lungara 29 in Trastevere, converted from a Carmelite convent in 1881. Its long facade is ochre-yellow: a lower storey of pale rusticated stone blocks, smooth render above, rows of tall rectangular windows with dark shutters and small white air-conditioning boxes, pilasters between the bays and a heavy cornice below the roofline. A stone-framed arched entrance stands near the centre of the ground level.

The structure was originally built as a convent in 1654 and later transformed into Rome's primary detention center in 1881 under Kingdom of Italy administration. This conversion marked the shift from religious to state control during the 19th century.

The name comes from the former convent dedicated to Mary as Regina Coeli, Queen of Heaven. Until recently, relatives of inmates gathered on the Gianicolo hill, by the lighthouse balcony a few dozen metres from the corner cells, and shouted messages to them; strong-voiced men took turns relaying the words for free, and police generally let the practice continue.

The building is visible from outside, but public visits are typically not permitted as it is an active detention facility. Visitors can observe the structure and its architecture from the Trastevere streets nearby.

The Gianicolo lighthouse balcony stands only a few dozen metres from the corner cells. Until recently, relatives gathered there at night and shouted news towards the prison; officers tolerated it if the messages were urgent, and strong-voiced volunteers relayed them in turn.