Rumeli Fortress

Rumeli Hisari is the most dramatic monument on the Bosphorus and the prelude to the conquest of Constantinople. In 1452 the young sultan Mehmed II chose the narrowest point of the strait, opposite the older Anatolian fortress on the Asian shore, and built this fortress in a famously short time, a matter of months, so that his guns could control all shipping to the Black Sea and cut the Byzantine capital off from supplies. Its curtain walls climb steeply up the hillside between three huge towers, traditionally named after the viziers who were responsible for building them, and smaller towers along the walls, enclosing a terraced interior that is now a garden of trees, paths and an open-air amphitheater. The setting is magnificent. From the upper terraces the view takes in the Bosphorus at its tightest, the second bridge, the wooden waterside mansions of the shore and the Anatolian fortress across the water. The fortress is a state open-air museum with a modest entry fee for foreign visitors, closed on Mondays, and the Museum Pass Istanbul is valid. Restoration work has been under way for some time, and at present it can restrict access to the high wall walkways and tower interiors, though the courtyard, gardens, viewpoints and a small mosque remain open. It sits on the coast road between Bebek and Emirgan, one of the most beautiful stretches of the Bosphorus, and makes the perfect goal for a shoreline walk.

Getting there: buses run along the coast road from Kabatas and Besiktas, a taxi from Taksim takes about twenty-five minutes outside rush hour, and the walk from Bebek along the shore takes about twenty minutes. The best way to arrive is on foot from Bebek, past the moored boats and the Ottoman waterside villas, so that the towers rise up ahead of you. Opening hours are longer from April to October and shorter in winter, with the ticket office closing an hour before the site; children under twelve enter free. Check the official information before you go if climbing the walls matters to you, as walkways open and close with the restoration program.

What to see: start at the bottom by the sea gate and climb through the terraces, pausing at each level for the view. Look for the minaret base of the small mosque in the center, which was the fortress chapel for its garrison, and the cannonballs displayed in the grounds. Read the panels on the 1452 construction and the siege that followed in 1453, when the fortress helped choke the city. On summer evenings the amphitheater has sometimes hosted concerts, which are worth looking out for.

Make a day of it: combine the fortress with breakfast in Bebek or nearby Arnavutkoy, a village of wooden houses on the water, then continue north to Emirgan Park, famous for its tulips in April. Many Bosphorus cruises pass beneath the walls, but only a visit on foot gives you the full sense of their steepness and scale. Pair it with Ortakoy and Dolmabahce on the way back for a full Bosphorus day by land. The Bebek shore has plenty of cafes and simple restaurants for lunch, and the coastal buses make it easy to return to Besiktas or Kabatas when you are done. Visiting on a weekday morning means you may have the upper terraces almost to yourself, which is the best way to appreciate how this steep, compact fortress was planned around the currents and the narrow channel below.