The Greensand Way follows the Greensand Ridge through Kent and Surrey in in the UK. Details here: https://en.wikipedia.org/wiki/Greensand_Way. It is 108 miles long with equal distance in Kent and Surrey, and is reasonably well marked with a few OS map and signage errors on the way.

This is a traverse of the central spine of the Sangre de Cristo range, from Lake Como to Methodist Mountain. The route comes in at 103 miles, with approximately 53,000' of vert and some 77 peaks along the way. The goal is to stay true to the ridge for as much of the route as feasible.

Some stats:

14ers: 5
13ers: 33
12ers: 18
11ers: 17
10ers: 4
Total peaks: 77

Total Miles: 103
Established Trail Miles: 9
Established Route Miles: 6
Off Trail Miles: 88
Vertical Gain: 53,000'

Daniel Fagerlund submitted the route, which is a 105km loop through the Vålådalen Nature Reserve:

The Haute Route Pyrenees (HRP) follows the French and Spanish border, starting in Hendaye on the Atlantic coast and finishing in Banyuls-sur-Mer on the Mediterranean. Large sections of the route remain unmarked.

Flat and fast gravel path. Used to be a railway. Starts in Oldcastle and heads south. Passes by Mcgregor, then curves east by Harrow. Continues east through Kingsville. Ends in Ruthven.

https://www.alltrails.com/trail/canada/ontario/chrysler-canada-greenway