Lifted from Alpentourer magazine’s GPS Tourenatlas 2018, some quite nice routes, all downloadable for free from here:
https://www.alpentourer.eu/atwp/wp-content/uploads/2018/03/gps-tourenatlas-2018.zip
1. Esch-sur-Sere (165 km)
2. Clervaux (120 km)
3. Vianden (175 km)
Plus separate jaunts, branching out from Luxembourg city
https://www.visitluxembourg.com/en
https://www.alpentourer.eu/atwp/wp-content/uploads/2018/03/gps-tourenatlas-2018.zip
1. Esch-sur-Sere (165 km)
2. Clervaux (120 km)
3. Vianden (175 km)
Plus separate jaunts, branching out from Luxembourg city
https://www.visitluxembourg.com/en