The University of Salamanca was founded in 1134 and given the Royal charter of foundation by King Alfonso IX in 1218. It is the oldest founded university in Spain and the third oldest university in the world in continuous operations. The formal title of 'University' was granted by King Alfonso X in 1254 and recognized by Pope Alexander IV in 1255.
Set of buildings that made up the university are situated around the square known as Patio de Escuelas. In this same square is the home of the Doctors of the Queen (15th century), whose façade is Gothic with Renaissance details and is now the Museum of Salamanca.
References:What an amazing structure. Who designed and built it?
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.