The first fort in Isein was built by bishop Atto of Freising in 784-811 AD. The current Burgrain castle dates from 1200s, when the lords of Burgrain built a four-winged building with keep and moat. The extensive additions and renovation was made in the 15th century by bishop Nicodemus.
After the secularization in 1804 Burgrain castle has been in possession of several owners. In 1906 it was converted into a home for blinds. Since 1919 it has been a private residence.
The castle church dates from 1719 and is richly decorated with rococo plasterwork.
See Burgrain from the Air
https://www.youtube.com/watch?v=EfFImys6EGw
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.