Ecotechnical Museum is placed in the listed area of the old sewage cleaning plant, which is one of the important objects of our industrial architecture. Part of the tours are visits to the underground of the main operating building, where the visitors will learn about the history of sewerage and cleaning of waste water. One floor higher, in the steam engine room, two operational Breitfeld & Daněk steam engines from 1903 can be seen. On special occasions, these are shown running. The operating lifetime of the plant was planned to end in the thirties of previous century, however, the plant served its purpose till 1967, when new modern mechanical-chemical treatment plant was opened on nearby Císařský island.