Enjoy breathtaking cityscape views from Istanbul Sapphire, one of Turkey's tallest buildings with 64 floors. Its 231-metre-high observation deck offers a unique perspective of the Princes' Islands, historically known as the Prinkipos Islands; the Bosphorus Strait, an internationally significant waterway linking the Black Sea to the Sea of Marmara; and iconic landmarks such as the Hagia Sophia Grand Mosque.