http://www.outdoorresearch.com/blog/stories/runners-inspiration-a-trail-gallery The Hardergrat is a 24 kilometer long ridgeline from Interlaken, to Brienz, Switzerland. The trail literally stays right on the edge of the ridge, sometimes knife edge in places with the sides dropping away for over 1000 meters. It is considered a classic one-day trail.
The arid Big Bend National Park may be a national park, but as one of the least-visited parks, it provides the isolation (and dramatic scenery) necessary for a journey of self-discovery. http://www.nps.gov/bibe/index.htm - Explore the World with Travel Nerd Nici, one Country at a Time. http://travelnerdnici.com
The Pacific Crest Trail, like its better-known eastern cousin the Appalachian Trail, is a narrow corridor of wilderness set aside by an act of Congress (The National Trails System Act, 1968) to preserve a place where hikers can commune with nature. Visit http://tellitonthemountain.com/ for more information