Yoros Castle dates back to Byzantine times that stands above the confluence of the Bosphorus and the Black Sea in Beykoz. The castle overlooks one of the narrowest stretches of the Bosphorus.
The site was originally settled by the Phoenicians and Greeks for trading and military purposes. Yoros Castle was intermittently occupied throughout the course of the Byzantine Empire. Under the Palaiologos dynasty in its later years, Yoros Castle was strongly fortified, as was the castle on the opposite side of the Bosphorus. A massive chain could be extended between these two points, cutting the Strait off from enemy warships in the same way that the chain across the Golden Horn was used to defend Constantinople during the last Ottoman siege by Sultan Mehmed II.
The Byzantines, Genoese and Ottomans fought over this castle for centuries. It was first captured by Ottoman forces in 1305, but was retaken by the Byzantines shortly afterwards. Sultan Bayezid I took the castle again in 1391 while preparing for his siege of Constantinople, and it was used as a base during the construction of Anadolu Hisarı, which was to prove more important in the eventual successful siege. In 1399 the Byzantines attempted to take back Yoros Castle. The attack failed, but the village of Anadolu Kavağı was burned to the ground. The Ottomans held the fortress from 1391–1414, losing it to the Genoese in 1414. Their forty-year occupation gave the castle its commonly used nickname - the Genoese Castle.
After Sultan Mehmed II’s conquest of Constantinople in 1453, the presence of the Genoese in such a strategic location posed a threat to the new Ottoman capital and within a few years they were driven out. Mehmed II then refortified the walls, and constructed a customs office, a quarantine centre and a check point, as well as garrisoning the site. Bayezid II (1481–1512) later added a mosque within the castle walls.
Under Osman III (1754–1757), Yoros Castle was once again refortified. Later, in 1783 Abdülhamid I added more watchtowers. After this time, the castle gradually fell into disrepair. By the time the Turkish Republic was declared in 1923, it was no longer in use.
The ruins of the citadel and its surrounding walls still exist. Yoros Castle make a popular day trip from the centre of Istanbul. The castle now open to the public, but the surroundings of the castle are a military area and closed to visitors.
References:The ancient Argos Theater was built in 320 BC. and is located in Argos, Greece against Larissa Hill. Nearby from this site is Agora, Roman Odeon, and the Baths of Argos. The theater is one of the largest architectural developments in Greece and was renovated in ca 120 AD.
The Hellenistic theater at Argos is cut into the hillside of the Larisa, with 90 steps up a steep incline, forming a narrow rectilinear cavea. Among the largest theaters in Greece, it held about 20,000 spectators and is divided by two landings into three horizontal sections. Staircases further divide the cavea into four cunei, corresponding to the tribes of Argos A high wall was erected to prevent unauthorized access into the theatron and may have helped the acoustics, but it is said the sound quality is still very good today.
Around 120 CE, both theaters were renovated in the Roman style.