One of Mittenwald's main attractions is the Leutaschklamm, an attractive gorge just to the south of the town. You pay a euro or so to go in, and follow a walkway as far as a waterfall, and then turn around and go out again. Now there is a new way of seeing the gorge - the new 'Geisterklammweg', which enters the gorge higher up and provides great views of the steep-sided valley from the new walkways.
Built at a cost of 1.4 million euros, the metal walkway winds its way for over half a kilometre up the gorge. Two bridges provide access to the paths on the other side of the gorge and provide rather dizzying views to the stream below.
It's not quite the Grand Canyon, and the Partnachklamm near Garmisch-Partenkirchen is perhaps still the more spectacular, but this is definitely worth a visit if you find yourself in the area - and Mittenwald is always a nice place to take visitors to.
The paths are currently all open, although this may change if it actually decides to snow for once. The link below tells you whether or not the path is open (the Wasserfallweg is the old path into the gorge and is only open between May and October).
Alpenwelt-Karwendel - Die Leutascher Geisterklamm
Auf dem Grenzweg durch die Leutaschklamm