Abu Simbel is a historic site comprising two massive rock-cut temples in Upper Egypt, near the border with Sudan. The twin temples were originally carved out of the mountainside in the 13th century BC, during the 19th Dynasty reign of the Pharaoh Ramesses II. Their huge external rock relief figures of Ramesses II have become iconic. His wife, Nefertari, and children can be seen in smaller figures by his feet. Sculptures inside the Great Temple commemorate Ramesses II's heroic leadership at the Battle of Kadesh.
The complex was relocated in its entirety in 1968 to higher ground to avoid it being submerged by Lake Nasser, the Aswan Dam reservoir. As part of International Campaign to Save the Monuments of Nubia, an artificial hill was made from a domed structure to house the Abu Simbel Temples, under the supervision of a Polish archaeologist, Kazimierz Michałowski, from the Polish Centre of Mediterranean Archaeology University of Warsaw.
The Abu Simbel complex, and other relocated temples from Nubian sites such as Philae, Amada, Wadi es-Sebua, are part of the UNESCO World Heritage Site known as the Nubian Monuments.
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.