Ruttenstein Castle was first time documented in 1209, in a deed issued by Duke Leopold for the Baumgartenberg Monastery, where it is mentioned under the name Rotenstein. The existing structure of the high castle, however, suggests that the castle is significantly older. The construction period likely falls in the first half of the 12th century, although this is not documented. It is probably a foundation of the Counts of Clam-Velburg.
The walls of the formerly massive pentagonal keep are now only partially preserved, tapering to a point and visibly towering over the site. The former residential wing in the west retains three of its walls. Above them, a viewing platform has been constructed, accessible via wooden stairs. Clearly recognizable, though also only partially preserved, is the early Gothic castle chapel located near the stone steps to the residential building. The main castle itself was protected on the north, south, and east by a mighty ring wall, which is still partially preserved today, and from which seven wall towers protruded.
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.