We took the 3:15 tour in English - tickets are purchased at the Tourist Info office, across the street from the Duomo. (Not the office for tickets to the Duomo, the one next door). From your gathering spot outside the ticket office, the tour guide will lead you to the locked entrance. The views to the south are beautiful. You can take photos once underground, but no videos. Our tour guide was very knowledgeable and we enjoyed learning more about the Etruscans and Romans