This museum traces the history of Lisbon's water supply, from Roman times until the present day and more particularly the Águas Livres (Free Water) project devised by the engineer Manuel da Maia. Until 1967, Lisbon's water was supplied by an aqueduct (1748) and the Barbadinhos steam pumping station, built here in 1880, a fine example of industrial architecture. One of the four steam engines on show is put through its paces for the benefit of visitors.