A Bosphorus boat tour is a nice thing to do in Istanbul. Get on the boat and start discovering the long waterway which separates Europe and Asia.
Almost all tours start from the Old City in Sultanahmet and cruise along the European side until the 2nd Bosphorus bridge and return back along the Asian coast. You will pass by Dolmabahce Palace, Ciragan Palace, Ortaköy Mosque, Bosphorus Bridge, Rumeli Fortress and Beylerbeyi Palace. You will aslo get to see some historical landmarks from a distance such as Hagia Sophia, Topkapi Palace, Maiden Tower, and Galata Tower.
