The Bosporus is one of the busiest and narrowest waterways in the world. It is one of two important straits connecting the countries located north of the Black Sea to Mediterranean countries for centuries. With its unique. beauty, magical atmosphere and special location at the meeting point between Asia and Europe, the Bosporus has been important in terms of security as well as the commercial, economic and social life of the city throughout history.

For this reason, historical buildings can be seen dotted on either side of the Bosporus as a precaution against attacks. The most famous of them are Anadolu Hisarı, commissioned by Ottoman Sultan Bayezid I, also known as Bayezid the Thunderbolt, and Rumeli Hisarı, commissioned by his grandson Sultan Mehmed II, also known as Mehmed the Conqueror.

Built between 1393 and 1394 as part of Sultan Bayezid I’s preparations for a siege on the then-Byzantine city of Constantinople (today’s Istanbul), the fortress of Anadolu Hisarı is situated at the narrowest point of the Bosporus. After Sultan Bayezid I’s plans to conquer Constantinople came to an end with his defeat in the Battle of Ankara, Sultan Mehmed II assumed the mission. Reinforcing the fortress and adding further extensions, Mehmed II ordered the construction of a sister structure to Anadolu Hisarı across the other side of the Bosporus to be named Rumeli Hisarı. Working together in 1453 to halt maritime traffic, the fortresses helped the Ottomans to achieve their aim of making the city their capital.

However, Istanbul already housed structures that made the Bosporus easily controllable even before the Ottoman period. One of them was Yoros Castle, which is located in the Anadolu Kavağı neighborhood at the northern end of the Bosporus in the Beykoz district of Istanbul and dates back to the Eastern Roman period.

Four spiritual protectors

In its long history, Istanbul featured stories of many evliyas or Muslim mystics. Today, people still visit the tombs of these religious figures in different districts of the city and commemorate their souls through prayer.

Among these religious figures, the tombs of Joshua (Yuşa in Turkish) in Beykoz, Yahya Efendi in Beşiktaş, Telli Baba in Sarıyer and Aziz Mahmud Hüdayi in Üsküdar are located at the entrance and exit of the Bosporus. These four tombs are believed to provide spiritual protection to the Bosporus and sailors traversing it in addition to the physical protection provided by various forts and structures.

It is said that when the Prophet Moses received a revelation from God that there was someone named Khidr who was more knowledgeable than him, he was tasked with meeting that person at the junction of two seas. Setting off for the meeting, Moses departs, bringing Joshua with him. However, when they get to the Bosporus, Joshua dies. After his death, he is buried on the highest hill with a view of both the Bosporus and Black Sea. Rumor has it that it was Yahya Efendi who discovered Joshua's grave after Joshua revealed its location to him in a dream.

Yahya Efendi goes to this hill, located in today’s Beykoz with a commanding view of the Bosporus from the Asian shore, and meets a shepherd there. He asks the shepherd whether something extraordinary happened in the area, to which the shepherd responds that there is a spot on the hill where his sheep never graze. With this information, Yahya Efendi tracks down the grave and surrounds it with walls.

The hill is called Joshua's Hill today and it houses a shrine containing a mosque and a tomb dedicated to Joshua. Locals believe the tomb is sacred and visit it to be healed from their illnesses. The mosque was commissioned by Grand Vizier Yirmisekizzade Mehmed Said Pasha in 1755 with an adjacent shrine. It was restored during the reign of Sultan Abdülaziz in 1863.

Physical protector

To the north of the hill lies Yoros Castle. Whereas the tomb of Joshua serves as a spiritual protector of the Bosporus, Yoros Castle was also built with the aim of controlling the entrance to the strait. The name of the castle, which is also known as Anadolukavağı Castle or the Genoese Castle, is said to be rooted in the word "hieron," meaning sacred place in Greek. However, it may be more accurate to say that the name Yoros comes from "oros," meaning mountain.

Despite what many think, Yoros Castle is not a Genoese structure. An inscription in Greek carved in the bricks in one of the towers of the castle implies that it is an Eastern Roman building. The castle passed into the hands of the Turks at the beginning of the 14th century. However, in 1348, the castle was captured by the Genoese, who were dominating the Black Sea trade route. At the end of the 14th century, it was taken by the Ottomans again, completely dominating the Anatolian side of the Bosporus.

Sultan Bayezid II, who repaired coastal forts in almost every part of the Ottman Empire or commissioned new parts, repaired Yoros Castle as well. He also had a place of worship, the Yoros Castle Masjid, built into it while the castle's warden, Mehmet Agha, commissioned a bath. Armenian writer Ğugas İnciciyan, also known as Ghukas Inchichean, once reported that there was a 25-home Turkish neighborhood in Yoros Castle at the end of the 18th century.

From east to west, Yoros Castle lies parallel to the Black Sea with a length of 500 meters (1,640 feet) today, treating visitors to an idyllic view of the strait and the ancient atmosphere of its ruins.