Halki Castle is located on the hill of St. Nicholas over the old village of Halki. It was built by the Knights of St. John in the 14th-15th century over the ancient Hellenistic citadel. From there they were able to control the sea routes, the harbor and the Trachean peninsula. Inside the castle are the ruins of the medieval church of St. Nicholas. At the gate the emblem of the Grand Master of the knights Pierre d’Aubusson (1476-1503) is engraved.
Today, the castle is accessed through a paved path from where the view is just fascinating. The back side of the hill is rough and its slopes lead to the sea. At the foot of the castle, there are three small chapels dedicated to Virgin Mary, to Saint Nicolas, and to the Holy Trinity.
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.