Janowiec Castle was most likely built by Mikołaj Firlej between 1508 and 1526, on a steep Vistulan hillside in Janowiec. It expanded by his son, Piotr, the Voivode of the Ruthenian Voivodeship. The bastion, used as a residence, was destroyed by the Swedish army in 1655 during The Deluge.
Although the following owners of the castle did their very best to rebuild the castle, the castle never managed to regain its former glory. In 1928, an archaeologist, Leon Kozłowski had taken over the castle, but his plans to reconstruct the castle were stopped by the Second World War. After the Second World War, the castle was left in its former state, being one of many private castles. In 1975, the castle was bought by the Nadwiślańskie Museum in Kazimierz Dolny in Poland.
References:Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.