In his introduction to Costantinopoli, the book written by Edmondo De Amicis and republished by Einaudi in 2007, Umberto Eco referred to Istanbul as "Una e Trina", [a Trinity of three cultures] describing it as a fascinating city of myths and legends, to be discovered little by little, wandering its winding streets, free to gaze and absorb the city's endless diversity. While researching this book dedicated to Istanbul for the On the Road series, as we strolled through the streets of this metropolis, we too realised that it represented a journey in space and time, through a myriad of different periods and civilisations. To gain a true reading of this piace, one must explore the multiple layers accumulated over the centuries and which continue to be generated at the present time, determined by an intricate weave of both conservation and modernisation. The exploration of Istanbul is divided into five itineraries; each one reveals the huge complexity of this capitai which coexists with its numerous identities. A long journey that begins in the historic centre, home to the majestic Basilica of Hagia Sofia, symbol of the city and its Byzantine architecture, moving on towards Beyoglu, a district with a strong European influence, rich in museums and art galleries. Here, the Istanbul Modern by Renzo Piano sits along-side monumental buildings from the Ottoman period, like the 16th century Ali Pasa mosque by Sinan, the Baroque Nusretiye mosque, the Tophane Kasri summer palace, and the Tophane-i Amire canon foundry; an excessive urban accumuiation where contemporary architecture contrasts with that of ancient civilisations, a characteristic that increases as one moves further north towards the districts of Besiktas and Sisli. The European part of the city flows on to the districts of Kagithane, Besiktas, Sariyer and Eyiip with some of Istanbul's most important infrastructures: the Fatih Sultan Mehmet Koprusu and Yavuz Sultan Selim bridges, true examples of avant-garde engineering, that connect the European and Asian sides of the city. This finally leads to the other shore of the Bosporus, in particular, the districts of Kadiktiy, Uskiiar and Atasehir, areas of the city under vast expansion, dense with contemporary architecture, where even the religious buildings are in contrast with the mosques in the historic centre. In this guide, we take the opportunity to pay homage to the complex territories which define a city that straddles two continente, which has been a melting pot of different cultures, religions, and aesthetics for centuries. We hope the suggested itineraries will act as inspiration, but also as an invitation to roam the streets of a city that, over the course of its history, has changed its name from Byzantium to Constantinople, to the present day Istanbul, without ever ceasing "to remain the same".