I recently discovered the Lieserpfad in the area Vulkaneifel. It is a lovely singletrack in a quit valley. One of the greatest beyond the alps.
There are different Routes you can drive depending on where you want to start and how long it should be. I didn’t try all but want to in the future.
Some short parts of the Track are quite hard to drive and I had to walk.
Find two versions of the Track below. I rode the second one. Resolution of the second one ist not so great in some parts of the valley but I managed to get back to the starting point.