Marmaray, the 13.6-km (8.5-mile) rail connection between European and Asian Istanbul via a tunnel beneath the Bosphorus, joins the stations at Yenikapı and Sirkeci in Europe with the stations at Üskudar and Ayrılık Çeşmesi in Asia—makes it possible to cross from Old Istanbul in Europe to Üsküdar in Asia in a matter of minutes.

The new underground stations at Yenikapı, Sirkeci, Üsküdar, and Ayrılık Çeşmesi make it easy for Marmaray passengers to connect to Istanbul's Metro, city bus, tram and ferryboat networks.