[1] Kropfsberg is a ruined hill castle in the municipality of Reith im Alpbachtal on a towering ridge in the Inn Valley above the village of St. Gertraudi.

Under Archbishop Konrad I of Salzburg, the first castle was built in the first half of the 12th century at the entrance to the Zillertal valley.

Archbishop Eberhard II von Regensburg [de] continued to expand the castle.

In the course of time Kropfsberg was twice expanded in a Romanesque style, but there were no major Gothic construction activities.

In the year 1592 the court seat of Kropfsberg was moved to Zell am Ziller, which led to the decline of the castle.

As a result of the fact that the castle was only inhabited by people and was no longer maintained, the first buildings collapsed in 1673.

In 1809, during the Napoleonic wars, Tyrol briefly passed to Bavaria by the Treaty of Schönbrunn before being absorbed into Austria in 1814.

A prehistoric hilltop settlement with shallow ramparts and small terraces was largely destroyed by the overbuilding of the medieval castle.

Built around a hexagonal courtyard, the Romanesque stronghold dates back to the second building, of which only the two keepers still exist.