The Pnyx is a hill in central Athens. Beginning as early as 507 BC, the Athenians gathered on the Pnyx to host their popular assemblies, thus making the hill one of the earliest and most important sites in the creation of democracy.
Pnyx is a small, rocky hill surrounded by parkland, with a large flat platform of eroded stone set into its side, and by steps carved on its slope. It was the meeting place of one of the world's earliest known democratic legislatures, the Athenian ekklesia (assembly), and the flat stone platform was the bema, the 'stepping stone' or speakers' platform. As such, the Pnyx is the material embodiment of the principle of isēgoría, 'equal speech', i.e. the equal right of every citizen to debate matters of policy.
Today the site of the Pnyx is under the control of the Ephorate of Prehistorical and Classical Antiquities of the Greek Ministry of Culture. The surrounding parkland is fenced, but the traveler can visit it free of charge at any time.
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.