Most of the book is one long day in Florence. At Porta Romana Langdon and Sienna find the police waiting, slip into the Boboli Gardens and run through the Vasari Corridor over Ponte Vecchio to Palazzo Vecchio, where Langdon hunts for a clue in a giant fresco. Today that route is not an open path: the corridor is visited only with a booked time slot, going in from the Uffizi and coming out in Boboli, the opposite way to the book, and Boboli and Palazzo Vecchio have their own tickets. From outside, Porta Romana, Ponte Vecchio and Palazzo Vecchio are easy to link on foot.
Then come Dante's streets, all a few minutes apart: the Badia Fiorentina, where the book opens, the Casa di Dante museum, the little church of Santa Margherita de' Cerchi, where visitors leave letters for Beatrice, Dante's great love, and the Baptistery, where the stolen mask turns up.
Then the chase moves on: St Mark's in Venice is about 2 hours from Florence by train, while Hagia Sophia and the Basilica Cistern are in Istanbul, a flight away. A few places come only from the 2016 film: the Istanbul University gate and two squares in Budapest, Fővám tér and Gutenberg tér, where the film shot scenes set in Italy. Each city is a trip of its own: in the Plan section, choose Florence, Venice, Istanbul or Budapest. Book the Vasari Corridor and the secret passages of Palazzo Vecchio ahead. Robert Langdon's adventure in Paris is The Da Vinci Code.