The Royal Mint (Real Casa de la Moneda) in Segovia was founded by Philip II and designed by Juan de Herrera. It now holds two museum spaces: the Museum of the Casa de la Moneda and the Aqueduct Interpretation Centre.
Located beside the Eresma River and the Alcázar palace, it is the oldest example of industrial architecture still existing in Spain. It operated as a Royal Mint between 1586 and 1869, and still conserves its hydraulic infrastructure intact, with a dam in the Eresma river. Part of the hydraulic system is on display in the outdoor courtyard, with a reproduction of the wooden channels and waterwheels which today, as in the 16th century, power the machinery.
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.