Handpicked experience · Istanbul
Istanbul, Turkey
The strait runs two ways at once — Black Sea water south on top, Mediterranean water north along the bottom — and a fortress at its narrowest point was built in four months to close it.
A waterway with two currents running in opposite directions
The narrows where a city was strangled in 1452
Timber mansions with the water at their foundations
Two continents visible from the same deck
Two hours that fit inside a half-day of sightseeing
Two hours on the water in Istanbul, running up the Bosphorus past the palaces, the wooden waterfront houses and the fortresses, with the city on two continents on either side.
The Bosphorus flows in two directions at the same time, and it has done so for as long as anyone has sailed it.
The Black Sea takes in a great deal of river water and is therefore less salty than the Mediterranean, so its lighter water spills south along the surface. Meanwhile denser, saltier water from the Sea of Marmara pushes north along the bottom, underneath the outgoing flow. Two currents, opposite directions, one channel — with a boundary layer between them that can be measured.
Fishermen here have worked with this for centuries; the surface catch and the deep catch belong to different bodies of water. There is a much-repeated story of Ottoman sailors dropping a weighted basket deep enough to catch the northward bottom current and be towed against the wind and surface flow. Whether or not anyone truly navigated that way, the physics it describes is real and it is happening under the hull.
At the narrowest point of the strait stands Rumeli Hisarı, put up by Mehmed II in 1452 — the year before he took Constantinople — directly opposite an older fortress on the Asian side.
The purpose was strangulation. Together the two forts closed the channel at its tightest, cutting the city off from Black Sea grain and reinforcement. Its Turkish name at the time was Boğazkesen, which reads as strait-cutter and equally as throat-cutter, and the pun was not accidental. It went up in about four months, and when a Venetian ship declined to stop and be inspected, it was sunk from the walls. The message was understood.
The yalı are timber summer houses built directly on the shoreline by Ottoman court families from the eighteenth century onwards, with the water reaching the foundations and boats moored at the door.
They were built of wood, which is why comparatively few survive: the older ones burned, and the rest need constant, ruinous upkeep against damp, rot and the wash of passing ships. The ones still standing are among the most valuable residential properties in Turkey, and from the deck you can see the whole range — immaculately restored ones next to shuttered neighbours quietly falling apart.
Sit on the upper deck if the weather allows; the whole point is the shoreline, and a window seat below is a poor substitute.
The strait is one of the busiest and most difficult waterways in the world, with tankers, ferries and fishing boats crossing in every direction and a sharp bend where the current runs hard. The boat will be moving among all of it. It is colder on the water than on shore, particularly in the afternoon when the wind comes down from the Black Sea, so bring a layer even in summer.
Open it to pick a date and work out the price.
What the fare covers, and what to budget for separately.
The practical detail, and the answers people actually ask for.
Yes, simultaneously. Lighter Black Sea water runs south on the surface while denser, saltier water pushes north along the bottom.
The Black Sea takes in a great deal of river water and is less salty. Lighter water floats out on top; heavier water slides in underneath.
Considerably. The surface catch and the deep catch effectively belong to two different bodies of water.
A fortress at the narrowest point of the strait, built by Mehmed II in 1452, opposite an older fort on the Asian shore.
Closing the channel. The two forts together cut Constantinople off from Black Sea grain and reinforcements the year before the city fell.
Boğazkesen — strait-cutter and throat-cutter at once. The pun was intended, and a Venetian ship that refused to stop was sunk from the walls.
Many are, and they rank among the most sought-after addresses in the country. Others stand shuttered and empty.
Wood burns and rots. The survivors need constant expensive upkeep against damp and the wash from passing ships.