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:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.