A famous alpine crossing in central Europe. Traversing three countries it connects Oberstdorf in the southernmost region of Germany with Meran, a beautiful city in south tyrol with mediterranean flair.
 

This is a pretty straightforward route that traverses a National Park (albeit a tiny one) and is a fun, very runnable 50k distance that has been done a number of times though doesn't seem to be popular. We didn't see a single person on the entirety of the Under the Rim Trail, which the park describes as unmaintained. There's certainly some blowdown in Agua Canyon (through an old burn) and a handful of washes to cross but they're easy to navigate.

The Chiemgautour is planned as a 4-day hiking-trip. It's 50 km, so it can be a one-day-trip. You are reaching four well known and beautiful peaks in the German Alps. It's the Kampenwand, Geigelstein, Spitzstein and Hochries. You will have a nice nature and beautiful views over the Chiemgau, the south of Bavaria and into the Alps. Most of the Tour is trail and path. There is no additional equipment needed, like ropes or crampons. Normal trailrunning or hiking-equipment will be enough.