So we drove down to Garmisch-Partenkirchen and visited the Partnachklamm, which is a 2300 ft. long gorge in the Alpes. Its walls rise to 260 ft. on both sides.
Walking through the gorge was really impressive (and nice and cool, about 77° F) and then hiked up the mountain.
On our way down, we passed the gorge again on an iron bridge that is situated 220 ft. above the river.
It was a really nice trip, especially for the dog. She was even allowed in the gorge as long as she stayed on the leash.