Leuchtenburg Castle (Castelchiaro) above Lake Caldaro towers into the sky in the surroundings of Castel Varco in the locality of Vadena. The castle was probably constructed in 1250 by the Lords of Rottenburg. The castle complex has been protected by a circular wall which protected the castle complex from assaults. Due to the fact that the position of the castle is not really well-protected it has presumably been constructed in order to impress.
Numerous castles of the Rottenburg leadership have been razed after the conflicts with Frederick IV, Duke of Austria, in 1410, but not Leuchtenburg, which was handed over to the sovereigns and in the following years was lent to officials of Caldaro. After 1610 Leuchtenburg remained uninhabited and started decaying.
Only in the 20th century the walls of the ruins were conserved. Leuchtenburg consists of a circular wall inside which there were several residential buildings. However, today these buildings could only be preserved to some extend. However, there are also well-preserved rests of the great hall with frescos dating back to the 15th century.
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.