Hydropolis is a place where diverse multimedia technologies, interactive installations, faithful replicas and models, as well as touch screens providing extensive information, serve one purpose – to show water from various fascinating perspectives.
Hydropolis was opened in December 2015. It is Poland’s only facility of this kind and one of very few worldwide – the exhibition is located in a historic, 19th century underground pure water tank covering a floor area of 4,000 m².
The tank served its original purpose until 2011, when it was made defunct. After the renovation and renewal it needed, the facility was converted into Hydropolis – the Centre for Ecological Education. The facility is entered on the list of historic buildings.
You can find some more info here https://hydropolis.pl/en/