The so called “Kornflaschen“ are historical grain silos in the town of Friedeburger Hütte (Named after the smeltery associated with the metal mining in the area). The first such silo was developed 1825, five additional in 1826 and 1829. In 1841 two more were built and two others purchsed until there were 10 silos in use. These silos were made of grouted slagstones and stored below ground in loose slag soil from the Friedeburger Smeltery. They were 9,5 m high and 4,5 m wide.  Securly stored in these spaces, this grain acted as a payment in kind harvest, which the miner and smelters received in times of need, along with their regular pay until the late 1870. The openings of the silos were kept one meter below ground and covered with a heavy stone plate to prevent moisture and robbers getting in.

2001 funds were made available to restore one of the silos. The restored area is open to visitors.