The Colossi of Memnon are two massive stone statues of the Pharaoh Amenhotep III in Luxor, which stand at the front of the ruined Mortuary Temple of Amenhotep III, the largest temple in the Theban Necropolis. They have stood since 1350 BC, and were well known to ancient Greeks and Romans, as well as early modern travelers and Egyptologists. The statues contain 107 Roman-era inscriptions in Greek and Latin, dated to between AD 20 and 250; many of these inscriptions on the northernmost statue make reference to the Greek mythological king Memnon, whom the statue was then, erroneously, thought to represent.
Scholars have debated how the identification of the northern colossus as 'Memnon' is connected to the Greek name for the entire Theban Necropolis as the Memnonium.
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.