Designed and built by the famous Florentine architect Luigi de Cambray Digny between 1827 and 1830, the Teatro Metastasio of Prato was founded to replace the Teatro dei Semplici, which had become obsolete. A distinguishing feature of the building is the semicircular shape of its outer facade, which corresponded to the horseshoe-shaped interior with four orders of boxes. The orchestra pit, the so-called "mystic gulf", a nineteenth-century innovation introduced to conceal the orchestra and thus artificially increase the sense of distance from the scene through a skilful optical illusion, was built only at a later time. Remodelled and modified over the course of the years, the theatre offers a rich program in which avant-garde productions predominate.