What is Bosphorus?
The Bosphorus is a strait about thirty kilometres long that joins the Black Sea to the Sea of Marmara and, through the Dardanelles, to the Mediterranean. At its narrowest, between the fortresses of Rumeli Hisari and Anadolu Hisari, it is roughly seven hundred metres across. That is the width of the boundary between Europe and Asia.
It is a working waterway, not a scenic lake. Roughly forty thousand vessels transit each year, including tankers that need tugs and daylight to make the turns, and the strait has some of the most demanding navigation of any commercial route in the world. It bends sharply in several places — the turn at Kandilli requires a course change of about eighty degrees — the current runs hard, and the city presses in on both banks.
There are in fact two currents. Salt water from the Mediterranean moves north along the bottom while fresher Black Sea water runs south on the surface, at times fast enough that small boats struggle against it. Fishermen have worked this pattern for centuries, and the migrating shoals that follow it are why the fish restaurants along both shores exist.
Three bridges cross it: the 15 July Martyrs Bridge, opened in 1973, the Fatih Sultan Mehmet Bridge of 1988, and the Yavuz Sultan Selim Bridge of 2016 at the northern end. Beneath it run the Marmaray rail tunnel and the Eurasia road tunnel.
How do you get to the Bosphorus?
You do not travel to the Bosphorus so much as reach a point on it. The simplest starting points are the ferry piers at Eminonu, Karakoy, Kabatas and Besiktas on the European side, and Uskudar and Kadikoy on the Asian.
The T1 tram runs along the European shore through Eminonu and Karakoy to Kabatas, which connects to the funicular for Taksim. The M2 metro serves Sishane and Taksim; the Marmaray line crosses under the strait and stops at Sirkeci and Uskudar.
For the villages further north, buses run up both shores, but traffic on the coast road is heavy and the ferry is usually faster as well as better. The long public ferry from Eminonu to Anadolu Kavagi near the Black Sea mouth is the classic way to see the whole strait.
When is the best time to visit the Bosphorus
Late spring and early autumn give the most reliable conditions: clear air, calm water, and light that works for photographs in both directions. May, June, September and early October are the months to aim for.
Time of day matters as much as season. Early morning is calm and quiet, with the fishing boats still out. Late afternoon into dusk is when the light turns and the palaces and yalis on the shore catch it; this is the crossing most people remember.
Winter has its own case. The strait under low cloud, with mist sitting between the hills and the ferries still running, is one of the city’s better sights, though a strong lodos can suspend services for a day. Summer afternoons are hot and hazy, and the water is the coolest place in the city.
What is the history of the Bosphorus?
The strait is a drowned river valley, flooded when the Mediterranean broke through at the end of the last ice age and filled the basin that became the Black Sea. The event was violent enough that some researchers connect it to flood traditions across the region, though the scale and speed remain debated.
Greek settlers understood what the crossing was worth. Byzantium was founded on the promontory at its southern mouth in the seventh century BC to control the traffic, and the city grew rich taxing it. Jason and the Argonauts were said to have passed the Clashing Rocks at the Black Sea entrance, which tells you how the ancient world regarded the passage.
In 1452 Mehmed II built Rumeli Hisari on the European bank opposite the older Anadolu Hisari, at the narrowest point, and cut Constantinople off from Black Sea supply. The city fell the following spring. The fortress took four months to build and its guns closed the strait to anything the sultan did not permit.
Under the Ottomans the shores filled with yalis, the wooden waterfront mansions of the court and the wealthy, and later with the nineteenth-century palaces at Dolmabahce, Ciragan and Beylerbeyi.
Passage is still governed by the Montreux Convention of 1936, which guarantees free transit for merchant shipping in peacetime while restricting the tonnage and duration of warship passage. It is the reason the strait cannot simply be closed, and it comes up in the news whenever there is a conflict in the Black Sea.
What is the Bosphorus famous for?
The 1973 bridge was the first fixed link between Europe and Asia in the modern era, and at the time the longest suspension bridge outside the United States.
The Marmaray tunnel, opened in 2013, runs beneath the strait at around sixty metres below sea level and is among the deepest immersed tube tunnels built anywhere.
The Bosphorus Cross-Continental Swim, held every summer, is the only race in which competitors swim from one continent to another while the strait is closed to shipping for the occasion.
Anadolu Hisari, begun in the 1390s, is the oldest surviving Ottoman structure in Istanbul.
What can you see in the Bosphorus?
Dolmabahce Palace, the nineteenth-century Ottoman court on the European shore, with a six-hundred-metre waterfront facade.
Rumeli Hisari and Anadolu Hisari, the two fortresses facing each other at the narrows, built to close the strait.
Ortakoy Mosque, small and ornate at the water’s edge beneath the first bridge, and one of the most photographed buildings in the city.
The yalis, the wooden waterfront houses, best seen from the water. The oldest, the Amcazade Huseyin Pasa yali on the Asian side, dates from the seventeenth century.
Beylerbeyi Palace on the Asian shore, the summer residence, smaller and easier to take in than Dolmabahce.
The Maiden’s Tower, on its islet off Uskudar, with more legends attached to it than documented history.
Anadolu Kavagi at the northern end, where the ferry turns around, with the ruined Yoros Castle above it looking towards the Black Sea.
Emirgan Park, at its best in April when the tulips are out.
Who are the most famous people in the history of the Bosphorus
Mehmed II built Rumeli Hisari at the narrows in 1452 and closed the strait, which decided the siege of Constantinople the following year.
Mimar Sinan worked along both shores, and the Sinan Pasha and Semsi Pasha mosques stand at the water’s edge.
Sultan Abdulmecid I commissioned Dolmabahce in the 1840s, moving the court out of Topkapi and onto the waterfront.
Ataturk spent his final months at Dolmabahce and died there in 1938.
Pierre Loti, the French naval officer and novelist, wrote about the strait and the Golden Horn in the late nineteenth century, and the hill above Eyup that carries his name is still a viewpoint.
Ahmet Hamdi Tanpinar and Orhan Pamuk both made the Bosphorus central to how Istanbul reads itself, the first in essays and the second in fiction and memoir.
What are the best things to do in the Bosphorus?
Take a cruise. This is the reason most people come to the strait, and it is the right reason. Seeing the palaces, fortresses and yalis from the water puts the city in an order that no amount of walking will.
Ride a commuter ferry. The crossings from Eminonu to Kadikoy or Uskudar cost a transport fare, take twenty minutes, and give you the same skyline. Tea is served on board.
Eat fish by the water. The villages on both shores are lined with restaurants. Kumkapi is the loud version; Cengelkoy, Kuzguncuk and Arnavutkoy are the good ones.
Walk a shore section. Ortakoy to Bebek on the European side, or Kuzguncuk to Beylerbeyi on the Asian, are both flat waterside walks of about an hour.
Go up for the view. Camlica Hill on the Asian side looks down the whole strait, and the tower there is the highest viewpoint in the city.
Visit the fortresses. Rumeli Hisari can be climbed, and the walls give a clear sense of why the narrows mattered.
Cross to Anadolu Kavagi. The full ferry run takes most of a day with a stop for lunch and the walk up to Yoros Castle.
Bosphorus nightlife
The strait has two evening personalities. Ortakoy, Kurucesme and Bebek hold the expensive end: waterfront clubs, terraces and restaurants where the view is priced into everything.
Kuzguncuk, Cengelkoy and Moda, across the water, are quieter and cheaper, with tea gardens and meyhanes along the shore where evenings run long without the door policy.
The simplest option is also the best value: an evening ferry. The crossing at dusk, with the minarets lighting up and the bridges changing colour behind you, costs the price of a transport fare.
Related guides
- Bosphorus Cruise vs Golden Horn Cruise Compared — A Bosphorus cruise sails the strait between Europe and Asia, passing palaces, fortresses and the bridges that link the two continents.
- Bosphorus Night Cruise: What’s Included? — A Bosphorus night cruise typically includes a fixed-menu dinner, a live Turkish show with a DJ set afterwards, and a table with a view of the strait.
- Bosphorus Dinner Cruise: What the Evening Looks Like — A Bosphorus dinner cruise is a three-hour evening on the water pairing a sit-down meal with a live Turkish show and open views of the strait.
Frequently asked questions about Bosporus
What is the Bosphorus?
The strait that separates Europe from Asia, running about thirty kilometres from the Sea of Marmara to the Black Sea. Istanbul sits on both of its banks, which is what makes the city geographically unusual.
What is the best way to see the Bosphorus?
From the water. The shoreline palaces, the wooden yali mansions and the fortresses were all built to be seen from a boat, and the view from the road gives you almost none of it.
What do you see on a Bosphorus cruise?
Dolmabahce Palace, the Ortakoy Mosque beneath the first bridge, Beylerbeyi Palace on the Asian shore, the Rumeli Fortress at the narrowest point, and the wooden yalis lining both banks.
Can you see the Bosphorus on a commuter ferry?
Yes, and cheaply. The regular ferries between Eminonu, Karakoy, Uskudar and Kadikoy cross the lower strait for the price of an ordinary city fare. What you do not get is the run north past the fortresses, the commentary, or a boat arranged so everyone has a view.
How long does a Bosphorus cruise take?
Short loops of the lower strait run around an hour and a half. The full public ferry north to Anadolu Kavagi and back takes most of a day, with a break there for lunch.
Which side of the boat should you sit on?
It matters less than people expect, because the boat turns and comes back down the other bank. In summer the more useful question is where the shade is.
The best Bosphorus Tours
Three kinds of trip cover most of what people want from the water.
A short cruise of an hour or two runs from Eminonu, Karakoy or Kabatas up to around the second bridge and back. It is the efficient option and fits into an afternoon. A Bosphorus cruise along this stretch takes in Dolmabahce, Ortakoy, the fortresses and the yalis.
A full-strait ferry from Eminonu to Anadolu Kavagi and back takes most of a day, stops for lunch at the top, and shows you the villages the shorter routes never reach.
A Golden Horn trip is the other direction entirely, inland past Balat, Fener and Eyup rather than out towards the Black Sea. The Golden Horn cruise is the quieter counterpart to the Bosphorus run and takes in a part of the city most itineraries skip.
Sunset sailings are the most popular and fill first, particularly in summer. Dinner cruises vary enormously in quality, and the ones with entertainment are a different proposition from the ones about the view. If you only want the scenery, the public ferry does the job for the cost of a bus ticket.
What is documented about the Bosphorus?
The Bosphorus runs 30 km (19 miles) between the Black Sea and the Sea of Marmara, narrowing to 750 metres between the Ottoman fortifications. (Encyclopaedia Britannica)
the current from the Pontus being confined and sweeping strongly against the headland, rebounds as if from a blow
— Polybius, Histories IV.43 (2nd century BC)