Wikipedia
This hike takes you on a neat tour of the Saarbrücken heights, including the battlefield site of Spichern. Spichern is in France, so the hike also includes several other exciting things, such as Westwall Fortifications and monuments from both the French and Prussian forces in the battle.
Rurseekatze
The Battle of Hürtgenwald was a rare Allied Defeat on the Western Front in WWII. Unlike other failed campaigns such as Market Garden or Kasserine Pass, the Battle of Hürtgenwald was a devastating meat grinder. The Kall Valley formed the initial assault vector for the allied attack. The steep hills and inclement weather created immense difficulties for Allied Forces. This hike combines the beautiful natural landscape of the Eifel with the traces of this devastating conflict.
CTHOE
The three Gleichen castles were the seat of the County Gleichen, in addition to fortresses belonging to the Abbot of Hersfeld and the Margraves of Thuringia. The castles guarded the important trade route of the Via Regia, and were subsequently besieged and destroyed multiple times over the course of history. Today, the three castles form a dramatic landscape in the Thuringian basin that is also easily accessible. Take a high-speed train from Frankfurt to Berlin through Erfurt, and you will see them as you pass by. This hike takes you on a trip to visit all three.
Muck
The Renaissance Palace of Lichtenberg in the Fischbachtal Valley is one of the few preserved Renaissance estates of the Hessen Dynasty. Though only a few interiors have survived to the present (and can be visited on request), the castle's exterior is remarkably intact, without additions or modifications from the Baroque or Romantic periods. The hike takes you around the town of Niederhausen to get the best views of the castle, and following that, it takes you through some of the beautiful landscapes of the Odenwald.
Dennis63
The Otzberg fortress was an outpost that traded hands between the Electoral Palatinate and Hessen. Though besieged many times, it was spared the targeted destruction faced by other regional castles. Today it houses a small museum with dramatic views from the surrounding country. This hike is about visiting the castle by public transport and collecting some of the views.