The Nahe Valley is one of the underrated natural gems of Germany. The river flows from the Saarland into the Rhine and cuts through a sandstone plateau, creating a series of beautiful gorges. The Kirner Dolomites are a series of cliffs and castles built on outcroppings above a tributary to the Nahe valley. This hike offers beautiful views and dramatic cliffs with lots of castles.
For an easy hike across some of the nicer farmland north of Frankfurt, there is the Monastery of Ilbenstadt. The monastery complex is mostly preserved and features a remarkable late Staufen Romanesque church and a Rococo gatehouse, hinting at the centuries of prosperity enjoyed by the monks here. Behind the monastery is a nicely preserved agricultural complex from the 19th century.
The underrated Nahe Valley has numerous tributaries that extend into the Hunsrück Highlands. This one which goes up and around the Simmertal valley, visits several dramatic outlooks of the landscape along with traces of ancient castles and industrial heritage.
The Red Moor is an ancient wetland in the highlands of the Rhön. Though much of it was drained or harvested for peat, today, it is a nice glimpse of the primeval landscapes of Europe. Including ancient deep ponds or "eyes of the moor," which served as cult sites for worship through to the end of the middle ages.
The Vogelsberg is a region in Upper Hessen known for its rolling and forested landscape. Much like the Odenwald and Westerwald, it's a mixture of small villages, forests, and agricultural land. This hike takes you up through this landscape to a highland moor, an ancient wetland with a unique natural landscape.