Where: Mertzig, Luxemburg
Constructed: 1964 - 2007
Accessible: No

Not a real castle, but an admirable building inspired by the medieval castle. Hidden in a valley in the Luxembourg woods lies the holiday home of Pol Gilson, who passed away in 2007. He built a wooden castle in 1964, but this was destroyed in a fire in 1973. Its replacement was a stone building, which self-taught Gilson built all by himself, with advice from professionals and by hiring heavy equipment (to dig out the lake around the house). At the end of 2020, Gilson's widow sold the water castle to the Mertzig municipality (for €450,000). The municipality opened the area, which had been private property for many years, to the public. It is not yet known whether the castle itself will also be accessible in the near future. The next step is to make Turelbaach Castle a national monument.