Gripenberg Castle (Gripenbergs slott) is a wooden manor house. It is considered to be the biggest wooden castle in Sweden and one of the oldest that remain today as well.
The castle was built in 1663 as a huntig seat for the field marshal Carl Gustaf Wrangel. Its architect is unknown, but there is some reason to believe, that it might have been Nicodemus Tessin the Elder. It is assumed that the castle's name is derived from the name of Wrangel's mother Margareta Grip and that Wrangel might have chosen it to commemorate her. By the end of the 17th century the castle was bought by Samuel von Söderling and remained in the possession of his family until today.
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.