These are Rome's largest catacombs. Buried in the 29km (18 miles) of tunnels were nine popes (venerated in a chapel known as il piccolo Vaticano), dozens of martyrs and thousands of Christians. They are stacked down, with the oldest on the top. Named after the banker, deacon and later pope Callixtus, who was administrator of the catacombs in the early third century, the area became the first official cemetery of the Church of Rome. The crypt of St Cecilia is the spot where this patron saint of music is believed to have been buried before she was moved to her eponymous church in Trastevere; the statue is a copy of the one in the church.