The toughest hundo in NY? This might be it. If you're looking for a soul-crushing, life-changing runventure hundo with incredible views and quad-thrashing climbs and descents.... this is the FKT for you. This rugged, technical mountain traverse is 96 miles long with 22,000 ft of climbing and summits 18 mountains on the east and west side of the Hudson. With the exception of 12 road miles and 4 miles of jeep roads, the rest of the traverse is on technical singletrack trails.

 https://www.mullerthal-trail.lu/en/mullerthal-trail

The Mullerthal Trail leads through the varied landscapes of the Mullerthal Region - Luxembourg’s Little Switzerland. On the three main trail routes, hikers can enjoy regional peculiarities as bizarre rocks, mossy forests and quaint stream valleys but also open pastures. Again and again the Mullerthal Trail leads to beautiful viewpoints and cultural sites.