Isenburg is a ruined castle located high above the valley of the Zwickauer Mulde. Archaeological finds indicate that this site already existed in the 12th century. Little is known about the history of spur castle and its violent destruction. There are no verified, documented references. Oral traditions - the first account dates to 1738 - called the Isenburg a 'robber castle,' the 'Old Castle' and the 'Iron Castle', from which its present name is derived. The castle had been destroyed by the 14th century and was never rebuilt. Its ruins were probably used from the 15th to 17th centuries as shelters for the local population during times of conflict. Around 1750, the remains of the castle were demolished to build the stone church in Wildbach.
The recommended way to visit the castle ruins is by foot from Hartenstein railway station which takes about 30 minutes. Only about 200 metres from the station is Stein Castle. At this spot the route crosses the Zwickauer Mulde river to a point immediately below Schloss Wolfsbrunn. Here the route turns left and winds through the Poppenwald upstream and parallel to the Mulde. After a short, but steep, climb known as 'Gentle Henry' (Sanfter Heinrich), the path forks. Keeping right, the route passes the Wildbach Church on an easy forest path. Here there are signs to the ruins which are another 700 metres further on.
The left-hand fork leads via a wild and romantic narrow path on top of the river bank of the Mulde to the same destination. This path is called the 'Raubrittersteig' ('Robber Baron Climb') and is one of the most attractive walks in the Mulde Valley.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.