Istanbul

The city where Europe and Asia meet across the Bosphorus, capital of Rome, Byzantium, and the Ottomans in turn. A single old peninsula stacks a Roman hippodrome, the great domed cathedral of Hagia Sophia, imperial mosques, and a covered bazaar older than most nations. Cross the Golden Horn to Galata and Beyoglu, the old European quarter of towers and tramlines. Read the layers at your own pace.