It's a race organisers predict no one might finish.
Starting tonight at 9pm, 25 of the world's fittest ultra marathon athletes, will take part in a 60 hour, 190km race in to the unknown.
"The competitors don't know where they're going ... they don't know what's involved until the last minute," race co-director Leroy de Beer says.
The only other event like it in the world is the Barkley Marathon held in the US state of Tennessee. A race held since 1986, only sixteen competitors have ever finished it.
"It's a bit like climbing an endless mountain ... you know you won't get to the top ... but you're still curious," race co-director Scott Worthington says.
Not only extremely physical, the race will push 25 competitors from across the globe to their mental limit as well, with a series of tasks and puzzles to complete at various checkpoints, on the rugged terrain.
Former navy seal Chad Wright is one who's flown over especially for the event.
"You know I've always wanted to go and do something that would potentially defeat me ... because I've never experienced that before," he says.
Despite saying they won't be surprised if no one finishes the race come Sunday, organisers are still hopeful.
"Scott and I think some will finish ... possibly, possibly not ... just have to wait and see," de Beer says.
The race was scheduled to start at midnight tonight, but will instead start at 9pm, simply to throw the competitors off.