The ruins of the Grottenburg (a castle built into a naturally occurring cave) Marmels are located on two rocky points high above the embankment dam that formed the Lai da Marmorera near the municipality of Marmorera.
 The entrance to the ruins is along a path that starts near the dam and then climbs steeply through the woods.
 The path may require an experienced climber and in wet weather may be inaccessible.
The ruins of the Grottenburg (a castle built into a naturally occurring cave) Marmels are located on two rocky points high above the embankment dam that formed the Lai da Marmorera near the municipality of Marmorera.  The entrance to the ruins is along a path that starts near the dam and then climbs steeply through the woods.  The path may require an experienced climber and in wet weather may be inaccessible.
Marmels Castle