SCOTTS VALLEY, Calif. -- The place is hard to find. You must drive into the mountains above Santa Cruz, following a road that turns from asphalt to dirt, then park at the top of a rise and look for a path whose entrance is deliberately concealed by brush.
A handful of men and women arrive here on a weekday afternoon in late spring, tramping through tall pines and occasional poison oak to get to an odd sort of playground.
Fashioned from plywood and metal pipe, the makeshift obstacle course looks like a children's jungle gym, only larger and considerably more dangerous. The man who built it offers his guests a word of advice.
"You have to go hard," David Campbell says. "Like you mean it."
Everyone laces up their shoes and soon they are swinging from ropes that hang from trees and scrambling up a sheer wall, reaching for the ledge on top. A mini-trampoline launches them toward rings that dangle overhead.
The practice session continues for hours as Campbell and his friends prepare for the season finale of "American Ninja Warrior," a summer reality show that has contestants racing through obstacle courses in various cities, hoping to make it to the national finals in Las Vegas where they can win $1 million by finishing the last stage.
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Only two people accomplished that feat through the first 10 seasons, but difficulty is part of the allure .
The NBC series has fostered a subculture of athletes who love testing themselves against the quirky, daunting obstacles. Some are former high school gymnasts or college track stars who are hungry to keep competing; others grew up strong and fast but never quite fit with traditional sports.
Finding a niche community to call home, they train in specialized gyms that have popped up across the country or maybe they wrangle an invitation from Campbell, a trim 41-year-old they call "The Godfather."
Shortly before the national finals -- which were taped in June and begin airing next week (Aug. 26) -- he convenes a workout at his homemade course. Brian Kretsch shows up, along with a Catholic lay worker known as the "Papal Ninja" and a stuntwoman, Jessie Graff, who ranks among the top female competitors.