The world's narrowest strait used for international navigation. It runs right through the heart of Istanbul, past the Istanbul Modern Art Museum, several Ottoman palaces, at least two fortresses, forested hills, and shore villages with Ottoman architecture.
It could be divided into 2 parts the Southern Bosphorus and Northern Bosphorus. The shores of the strait are heavily populated, straddled as it is by the city of Istanbul (with a metropolitan area in excess of 12 million inhabitants) which extends inland from both coasts. The strategic importance of the Bosphorus remains high.
It is a major sea access route for Russia. Control over it has been an objective of a number of hostilities in modern history, notably the Russo–Turkish War, 1877–1878, as well as of the attack of the Allied Powers on the Dardanelles during the 1915 Battle of Gallipoli in the course of World War I.
The waters of the strait are traversed by numerous ferries. Two suspension bridges cross the Bosphorus. The first of these, the Bosphorus Bridge, is 1,074 m (3,524 ft) long and was completed in 1973. The second, named Fatih Sultan Mehmet (Bosphorus II) Bridge, is 1,090 m (3,576 ft) long, and was completed in 1988 about 5 km (3 mi) north of the first bridge.
The Bosphorus Bridge forms part of the O1 Motorway, while the Fatih Sultan Mehmet Bridge forms part of the Trans-European Motorway. A cheap way to explore the Bosphorus is offered by the public ferries that traverse the Bosphorus from Eminönü on the historic peninsula of Istanbul to Anadolu Kavağı near the Black Sea, zigzagging between the Rumelian and Anatolian sides of the city.
It is also possible to experience the Bosphorus by taking a regular ride in one of the public ferries that travel between the European and the Asian sides. It is also possible to travel by the privately owned ferries available between Üsküdar and Beşiktaş or Kabataş. There are also tourist rides available in various places along the coasts of the Bosphorus.