The castle was built in 1149 by Otto von Machland who owned all of Upper Austria.
At that time it was a fortress consisting of two towers over 30 meters high. These two impressive buildings, one round and one rectangular, still exist in the very same shape today.
Soon after Otto von Machland died, the castle fell into the hands of robber barons. They were feared by the people of Upper Austria and excommunicated by the church. During the middle ages the ownership and construction of the castle changed several times until in 1454 the forefathers of the Counts of Clam arrived
During the 30 year-war the Clam family had their own private army to defend the castle. In these times of turmoil and revolts Clam village also suffered a lot and was burned down several times.
Clam was besieged many times but no hostile troops ever managed to capture the castle. However, in the mid 17th century when the war was over, the castle was in a very bad condition.
Under the regency of Johann Gottfried of Clam it was possible to renovate the entire castle. He started to transform the functional fortress into a comfortable castle as we see it today. He also built a church, a hospital and water pipes for the citizens of the village.
In the 18th century the wings housing the administration, the coaches and the horse stables were built. Today these wings form the outer yard.
Fortunately Clam castle also survived both world wars unharmed. Only the nuclear shelter, built in one of the castle’s cellars, is a reminder of the 20th century.
Besides the Castle the estate includes several farmhouses, a riding school, a hydropower plant, farmland and forests.