The ancient Odeon of Thasos, an conservatory in the ancient city of Thassos was built in Roman times. The building, which was discovered in 1929 gives us the impssion of a monumental building even though its biggest part is under the modern road of the town with only its lower part visible and the first rows of seats. It is certain that in ancient times it would have been an imposing edifice. It is made of marble and situated in the south of the ancient Agora.
The building consists of a hollow with two rows of seats, forming a semicircle, one orchestra and a stage structure. The orchestra is not paved and from the byways survived the two walls that support the ground at the edges of the hollow.
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.