The main attraction in Powys, Wales is a bog—and many of the region's visitors are apparently fine with this. That’s because the county’s enterprising residents have managed to turn mud into money with the World Bog Snorkeling Championships, a quirky annual competition that invites mask-wearing, flipper-clad contestants from around the world to swim across a dirty Welsh wetland known as Waen Rhydd.

Three decades ago, locals invented the competition hoping to draw new tourists to the former spa area. Health-conscious out-of-towners once flocked to its salubrious sulfur waters, but the region saw a decline in visitors as modern medicine advanced, reports Smithsonian.com.

To revitalize Powys, townspeople came up with the concept of “bog snorkeling." The stunt was successful. According to the BBC, individuals from England, Wales, Ireland, Australia, and America have competed in past events.

Last month, more than 100 people participated in the 2015 World Bog Snorkeling Championships. Hundreds of onlookers cheered as the snorkelers, clad in quirky costumes, masks, and breathing apparatuses, sprinted across two lengths of a 55-meter peat bog.

All in all, the event sounds like some good, not-so-clean fun—and like a creative way to rejuvenate the sleepy marsh region's economy.

[h/t Smithsonian]