Awful company and service, proceed at your peril! The Viator system let us book a tour to the Sistine on a closed day. Those tickets cost over £200. We were only in Rome for 2 days, 1 night, and the Sistine was a priority for my husband on his 50th birthday. When the Sistine chapel tour operator called to tell us, the only other time they had was at the same time as the Colloseum booking time. I tried to contact customer service and the tour operator who both refused to accommodate us and firmly stuck to cancellation policies. This was no fault of our own and entirely due to the Viator system allowing us to book another expensive tour for the Sistine on a day that was closed. For this reason I would never recommend Viator. They claimed they wouldn’t know if it was a closure day, which is awful for a booking system and ruined our organised trip and tour of the Colosseum and our planning for the time we had in Rome. Their customer service is awful and so unhelpful. We lost our money and the opportunity to see the Colosseum. Never use this company.