The Roman-era shrine to the god Mithras, hidden beneath Palazzo Barberini, will welcome visitors on guided tours every Saturday.The Mithraeum at Palazzo Barberini, one of the city's most important monuments to the cult of Mithras, reopens to the public on Saturday 3 October.  Visits are by guided tour only, with three sessions every Saturday at 10.00, 11.00 and midday. Each tour lasts 45 minutes and is limited to 20 people.   A 1930s discovery The Mithraeum was found in 1936 during construction work on the Palazzina Savorgnan di Brazzà, and lies in the building's basement. It is a significant monument from the Roman imperial era, dedicated to Mithras, a deity of Iranian origin. He was initially associated with guaranteeing pacts and agreements and later took on a strong military character. The sanctuary was created by reusing existing structures from the 2nd century AD. It is a compact space, 11.85 metres long and 6.25 metres wide, with a barrel vault and side benches (praesepia) where participants in the rituals would sit. Rare frescoes The shrine is notable for its elaborate fresco decoration, which has few parallels in the Roman world. Comparable examples include the Mithraea of Marino and Capua and, in Rome, that of Santa Prisca.   Il Mitreo Barberini riapre al pubblico sabato 3 ottobre.Gli accessi si terranno solo il sabato con visita guidata, alle 10:00, 11:00 e 12:00. Tutte le info: https://t.co/4xPWCkr565Biglietti disponibili al link: https://t.co/C4UmXlAyfM pic.twitter.com/Fh9X3qxzsp — Gallerie Nazionali Barberini Corsini (@BarberiniCorsin) October 1, 2026   The decoration is built around a depiction of the heavens, with zodiac signs and personifications of the Sun and Moon, along with ten side panels (pinakes) illustrating episodes from the life and sacred deeds of Mithras. At the centre is the tauroctony, the ritual scene in which the god, flanked by the torchbearers Cautes and Cautopates, slays the bull. It is the focal point of Mithraic symbolism and of the shrine's whole decorative scheme.   Thomas Clement Salomon, director of the Gallerie Nazionali di Arte Antica, said the reopening marks an important moment for the understanding and promotion of Rome's archaeological heritage. He said protecting a site like this requires a constant balance between conservation, research and public access. Tickets A ticket for the Mithraeum alone costs €7 (€2 entry plus €5 for the guided tour). Visitors aged up to 25 and others entitled to free admission pay €5, covering the tour only.   An integrated ticket also covers the collections of Palazzo Barberini and the Galleria Corsini. It costs €17 for adults, €7 for 18 to 25-year-olds, and €5 for under-18s and others entitled to free museum entry. The €5 Mithraeum tour fee is included in all cases.   Tickets can be bought online through CoopCulture. The Gallerie Nazionali di Arte Antica is at Via delle Quattro Fontane 13. Photo courtesy Gallerie Nazionali di Arte Antica - Palazzo Barberini.