According to Greek mythology, Troezen came into being as a result of two ancient cities, Hyperea and Antheia, being unified by Pittheus, who named the new city in honor of his deceased brother, Troezen. The ancient city of Troezen was one of the first cult centres in honour of the sea god Poseidon (in Greek mythology Poseidon is a forebearer of the former king Troezen after whom the city was named).
In 580 BC and in the face of the advancing Persian army Athenian general Themistocles proposed to the city assembly that all the women, children and elderly residents of Athens be evacuated to Troezen while able bodied men were sent to fight the Persians or to man the Athenian fleet. Although Athens was subsequently destroyed its citizens were spared.
During the Classical and Hellenistic periods numerous temples and other buildings were constructed in Troezen including a complex of buildings forming a sanctuary to Asclepius although this was somewhat overshadowed by its rival at nearby Epidauros. Other temples were dedicated to Artemis, Hippolytus, Athena and Aphrodite, traces of which can be found in a forest near Troizina.
In 230 BC the volcano at nearby Methana erupted causing severe earthquakes which destroyed many of the temples and buildings at Troezen leading to a decline of the sanctuary to Asclepius. During the Roman era many of these buildings were restored but as Christianity became predominant material from ancient buildings was used in the construction of churches as can be seen in the Diocese church which dates to the 6th century AD.
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.