Most cruises offer excursions to suit all types, from a city tour of Barcelona to see Gaudi’s architecture (about £40), to a boat ride from Sorrento to Capri (about £70), to a tour of the Acropolis and other treasures in Athens (about £50), to a tour of Rome – from the port of Civitavecchia – including the Vatican Museum and the Sistine Chapel (about £150).