The most tiring thing about the zipline was the walk through the jungle downhill, fully geared up, to the first traverse. By the time we got to it, we were all so weary and sweaty that we couldn't chicken out if we wanted to 'cause no WAY could we walk the 15 minutes back up hill the 300-500 feet or so that we'd dropped in elevation. In this pic you can see how we had to snake single-file downhill to line up for the first run (on the right you can see one of the workers zipping off to the right).