The former castle of Altenstein lies on a 452 m high peak above the Weisachtal valley. The castle ruins of Altenstein were first mentioned in the year 1225. The square castle keep still demonstrates this early history. The mighty fortified wall with its rounded corner and gate towers on the northern frontal ditch date back to the Hussite era. Some of the cellars and vaults are still preserved, despite being overlaid up to three times. They reveal a special feature of the Altenstein Castle: The castle of Altenstein was a typical example of a so-called “Ganerbenburg”, which meant it was occupied by several families at the same time. The Gothic windows of the former castle chapel (dating back to the year 1438) are among the most photographed images of the region. The ruins were restored between 1999 and 2003.