The are actually two castles in Schellenberg, the Upper Castle and the Lower Castle. We only visited the Upper Castle which is located in the hamlet of Hinterschloss. The Lower Castle is found just a few kilometers away and is the smaller one.
The Upper Castle was built end of the 12th century. In 1405 the castle was partly destroyed but restored. In the 16th century the castle then more and more fell into ruins. Since 1956 the castle belongs to the society of history for Liechtenstein (Historischer Verein für das Fürstentum Liechtenstein) who worked on excarvating and preserving the castle, so that today you here find nice castle ruins. It's not that much left, but I like such little ruins, it also would be a perfect place for a picnic!
The castle is always open, there's no admission.