Construction of the current fortress began in 1077 under Archbishop Gebhard von Helfenstein, as a basic bailey with a wooden wall. Excavations show a Roman fort at the highest point of the site. It measures 820 feet (250 m) long and 490 feet (150 m) wide, and the article calls it one of the largest medieval castles in Europe.
Ring walls and towers were built in 1462 under Burkhard II von Weißpriach. From 1495 to 1519 Leonhard von Keutschach expanded the fortress, installing state apartments on the third floor from 1498, with coffered ceilings, and later a chapel with a star vault. External bastions were begun in the 16th century and completed in the 17th, partly out of fear of a Turkish invasion.
The Reisszug, described in 1515, is an early freight funicular, probably the oldest operational railway in the world. The fortress was besieged once, in 1525, and surrendered without a fight to French troops in 1800.
Comments