Kathmandu, April 6 -- There are certain activities that demand absolute focus. The surroundings blur as vision narrows, tension rings in the ears. The closer to danger, the more exciting it gets.

Thrill is what adventure sports like mountaineering, canyoning and white water rafting are all about. Now, a new kind of outdoor activity is taking advantage of Nepal's vertical terrain and scenery: mountain biking.

The sport is going viral as passionate, trailblazing Nepalis turn what used to be trekking paths into biking trails, and post GoPro videos of their adventures. Now, the sport is going international and at the forefront is Phaplu Mountain Bike Club that held its second Enduro Ratnange Race in March.

"Last year was all about proving...