St. Jørgensbjerg church is the oldest preserved stone building in Denmark. Built of travertine circa 1100, it may have been inspired by the Roskilde's cathedral predecessor, a travertine church from 1080, built by Bishop Svend Nordmand. The bricked-up north door of the church may also stem from its predecessor from circa 1040, which was investigated in excavations undertaken in 1953-54. If it does, the north door is Denmark's oldest piece of medieval architecture.
The slender billets at the corners and in the middle of the nave are quite unique. Such billets are only found in wooden churches, hence its name 'a fossilized wooden church'. There are many interesting details in the interior of the church. A model of a medieval merchant vessel, a so-called 'kogge', has been engraved in the wall.
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.