The liechtensteinklamm, in St. Johann im Pongau, is a nine-hundred-foot deep cleft in the Austrian Alps. Intensely blue water cuts through the layers of limestone and slate, hollowing out a twisting, undulating path. There's a walkway, and a lot of tourists, and the whole thing is very much worth an hour of your time.
The tunnels and bridges were constructed in 1875 by the Alpine Association, with the help of Johann II, prince of Liechtenstein. The prince had a hunting cottage nearby and supposedly became quite excited about the project. A gift of six hundred guilders made the walkways possible, and got the chasm named after Johann.
It takes, maybe, twenty minutes to walk the length of the boardwalk - it's very easy and secure, with gentle uphill grades and handy railings. In reality, nobody does the walk that quickly. It's a stroll, really, with lots of places to stop and look up at the distant sliver of sky, down at the rushing water and around you at the hollows and layers of rock. The air is cool and misty, which was refreshing on a hot, May day.
As the path heads upstream, the water noises get louder and deeper. The current quickens and the passageway narrows. Finally, the walls fall away and the gorge opens up into a round, green bowl. A waterfall spills from somewhere above, joining the stream with a crash. There are some picnic tables here, and a nice platform to sit on.