Istanbul

Istanbul is the only city in the world that straddles two continents, with 15 million residents making it Europe's largest city by population. Its street food scene -- from balik ekmek fish sandwiches on the Galata Bridge to Syrian-influenced lahmacun in Fatih -- costs a fraction of Western European equivalents, while the Archaeological Museum holds one of the world's largest collections with over 1 million artefacts across its three buildings.