Located in Rome, the Catacombe di San Callisto is one of the most historically significant and important underground cemeteries in the world. Built in the 3rd century AD, this sacred burial ground was once the official cemetery of the Church of Rome, where half a million Christians were buried, including 16 popes and countless martyrs. Today, people can explore crypts such as those of St. Cecilia, Pope Melziades and St. Gaius and St. Eusebius, while learning about the fascinating symbols, history and traditions that surround this sacred site. Guided tours are also available. For anyone wanting to experience a truly captivating slice of history and spirituality, Catacombe di San Callisto is a must-visit.