The Belvedere on the Pfingstberg is a palace in the northern part of the New Garden in Potsdam, atop Pfingstberg mountain. It was commissioned by Friedrich Wilhelm IV and is only one part of an originally substantially more extensive building project. The twin-towered building was modeled on of Italian Renaissance architecture, and it was built between 1847 and 1863 with an interruption from 1852 to 1860. From sketches of from the king, the architects Ludwig Persius, Friedrich August Stüler and Ludwig Ferdinand Hessian drew up details plans. The garden architect Peter Joseph Lenné was responsible for the design of the grounds.
The building fell into disrepair, but was repaired between 1988 and 2005 by a group of local residents. Today, the Belvedere is open for tourists.
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.