Trail bike ride

When I first viewed this video, I was reminded of my previous posts about uber-scary hikes at Mt. Huashan and at El Caminito del Rey.  The difference in this video, of course, is the bike.  As a lifelong hiker, I have a certain degree of aversion to those who abuse foot trails with motorized transport - especially the ATVs that braid trails and disrupt wetlands.

The trail itself is spectacular, and it appears to have been subject to extensive repair and maintenance work over probably decades (or centuries?) of use.  Can anyone offer a suggestion re the location?  Are there any clues from the audio?