Yoros Castle

Yoros Castle stands near the meeting point of the Bosphorus and the Black Sea within the Beykoz district of modern-day Turkey. Its earliest known settlers were Phoenicians and Greeks, who established the location as an important center for trading and defense. In antiquity, this area earned the name “Hieron,” meaning “sacred place,” highlighting the presence of temples and altars dedicated to deities such as Apollo and Zeus.

The fortress itself likely dates to the Byzantine era, with evidence pointing to significant construction or renovation during the reign of Emperor Manuel I Komnenos. This period saw efforts to strengthen the region’s defenses against potential Viking incursions targeting Constantinople. Through the centuries, Yoros Castle served as a vital stronghold controlling naval passage along the Bosphorus, allowing those in command to monitor and collect tribute from ships entering or leaving the Black Sea.

Throughout its long history, control over the castle shifted among powerful actors. The Ottomans first captured the fortress in 1305, but it frequently changed hands, including a period in the late 14th century when the Genoese held it. This era contributed to the site’s alternate name, “Genoese Castle” (Ceneviz Kalesi). Eventually, by the late 1300s, the Ottomans regained permanent control, using Yoros as a military base during the siege of Constantinople. Under Sultan Bayezid I, the fortress’s walls were reinforced, and later Sultan Bayezid II commissioned the restoration of fortifications and the construction of a small mosque within the castle grounds. Subsequently, the fortress commander Mehmed Agha added a bathhouse.

The fortress endured damage from an earthquake in 1509 but received repairs by 1576, which included restoration of the mosque, water supply facilities, and the bathhouse. Yoros Castle remained in military use until the 19th century, when its strategic importance declined. The surrounding area also holds religious significance, notably the nearby Hill of Saint Joshua (Yuşa), a site containing a tomb traditionally linked to Joshua ibn Nun. This tomb attracts Christian, Jewish, and Turkish Sufi pilgrims and features a mosque and terrace restored in 1863 by Sultan Abdulaziz.