Partnach Gorge (German: Partnachklamm) is a deep gorge that has been incised by a mountain stream, the Partnach, in the Reintal valley near the south German town of Garmisch-Partenkirchen. The gorge is 702 metres (2,303 ft) long and, in places, over 80 metres (260 ft) deep. It was designated a natural monument in 1912. [wikipedia]
Fairly easy walk through the beauty of nature. You can visit the official homepage from them to get more information. The entry ticket costs 5 EUR per person, if you are a group of more than 15 people, it's 4 EUR per person.
It usually very wet in the gorge, so don't forget your rain jacket and be careful with your mobile and camera.