Meredith Quinlan submitted this route:

The route starts at the Northern-most Lighthouse Hraunhafnartangi, which is metres off the Northern-most point in Iceland and travels through the wilderness finishing down at the Southern-most Light house, Dyrhólaey, also metres from the Southern-most point in Iceland. Its length is approx. 560 km. In principle this is an open course route from lighthouse to light house but we have a variation that follows the East-coast which is much longer.

Established by EriK Schlimmer in 2010, the Trans Adirondack Route is a primitive pathway that traverses New York State’s Adirondack Park, the largest State Park and forest preserve in the Lower Forty-Eight. Running 240 miles, few footpaths in the Northeast are longer, and none are wilder. There is an FKT article that covers the route.

This classic route crosses the High Sierra, from Road's End (near Cedar Grove) on the west side, to Onion Valley (above Independence) on the east side. 

Starting in the depths of King's Canyon at 5000 feet, the route climbs the rugged Bubb's Creek Trail and a portion of the John Muir Trail, and culminates with the crossing of Kearsarge Pass (11,800 feet) before descending to the Onion Valley Trailhead (9200 feet).

Michael Lutz submitted this route which is in Bavaria, in the foothills of the Alps:

The Koenig-Ludwig-Weg was opened in 1977. With it's length of 120km it crosses all regions and villages that represented an important part in Ludwig's (who became king in 1864) life. The path starts at Starnberger See (where the king died in 1886) and ends in Fuessen near the famous Neuschwanstein Castle.