The ancient theatre of Lindos lies at the foot of the west slope of the rock of the Lindos acropolis. It had 19 rows of seats, most of them carved into the rock although somewere built, as were the endmost cunei and the side retaining walls, which do not survive. Today only the rock-carved sections are preserved: the circular orchestra, the three central cunei of the lower cavea and parts of the two neighbouring ones, and the central section of the upper cavea. The orchestra of the theatre is circular, also carved into the rock.
The theatre is dated to the 4th century BCE and had a capacity of 1,800-2,000 spectators. It is connected to the great city festivals in honour of Dionysos, the Sminthia, which included theatrical, musical and athletic competitions, processions and sacrifices. In the 3rd century BCE, directly adjacent to the theatre was built the Tetrastoon, a rectangular building with an internal colonnade, perhaps a sanctuary of Dionysos Smintheus.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.