Probably The Toughest Event On the Planet
Tough Mudder events are hardcore 20 km-long obstacle courses designed by British Special Forces to test your all around strength, stamina, mental grit, and camaraderie. With the most innovative courses and half a million inspiring participants, Tough Mudder is the premier adventure challenge series in the world.
Sydney – Sat 22 Sept & 23 Sept, 2012
http://toughmudder.com.au/