On a summer evening in Winsum, a crowd of several hundred people lines the bank of a narrow canal. A young man sprints toward the water, plants a twelve-metre pole in the mud, and begins climbing hand over hand as he swings across. He lands cleanly on the opposite bank, 22.41 metres from where he started. The crowd erupts.

Fierljeppen, literally "far leaping", is one of Friesland's oldest traditions. It began as a practical way for farmers to cross the canals that divide the flat, watery landscape. Somewhere along the way it became a competitive sport, with national records, formal competitions, and devoted fans who follow the circuit each summer.

This season has been exceptional. Attendance is up 40% from five years ago. Youth participation has doubled since a school programme introduced fierljeppen alongside football and swimming. Three athletes under the age of 22 are competing at the national level.

What explains the revival? Those close to the sport point to a growing appetite among young Frisians for something distinctly their own. In a media landscape dominated by Dutch and English content, fierljeppen is one of the few things that is unmistakably, irreducibly Frisian.

It requires no translation.