Stephan Siegrist and the Matterhorn slackline
Video of Swiss alpinist Stephan Siegrist and the slackline traverse on the Matterhorn (4478m).
How can you slackline between two countries? Perhaps there are easier ways, but Stephan Siegrist's idea is certainly original: between the Italian and Swiss summits on the Matterhorn. Also known as Cervino. But did they remember to check his passport ;-)