Piazza della Madonna dei Monti

This guide to Piazza della Madonna dei Monti in Rome opens in 1579, when workers demolishing a derelict convent wall in the old Suburra slum found a hidden fifteenth-century fresco of the Virgin Mary beneath the plaster. It follows how the discovery reached Pope Gregory XIII, who commissioned Giacomo della Porta to build the church you see today around it. You'll also hear about the plain travertine fountain Pope Sixtus V added a decade later for the square's market traders.