The Barbarossaweg is a fully marked German hike between Hessen and Thüringen (X8). It starts in a beautiful village called Korbach. Korbach is filled with houses that are build according to traditional craft (half-timbered houses, so called "fachwerkhäuser"). The route is filled with both history and art. It is an ''Ars Natura" route so there are pieces of art amongst large sections of the trail. The concept was already laid out in 1930 but due to the division of Germany in ''East" and "West" the trail was long not fully accessible in the 1960ies. In 1994 the route was revived and the finish is now at the beautiful Kyffhäuser denkmal (memorial), a landmark of epic proportions. According to the myth, Kaiser (Emperor) Friedrich, nicknamed "Barbarossa" - due to this red beard- is resting here. He has already been sleeping there for thousands of years and as long as the black ravens are flying around he will continue to do so. The route thus crosses former East and West and has plenty of heightmeters (around 6000hm). There are plenty of climbs and the trail primarily consists of "Mittelgebirge" (Freely translated as: low mountain range). You pass mines, castles, ruins, historical landmarks, monuments, lakes, steep climbs, dense forrest but also farms, traditional towns, and hardly encounter anyone (apart from wild animals) for days.
For further reading I can recommend the following literature:
https://www.traildino.com/trace/continents-Europe/countries-Germany/trails-Barbarossaweg_
https://www.komoot.nl/tour/618120796