Vattenpalatset, Public bath in Eskilstuna, Sweden

Vattenpalatset was a public bathhouse at Drottninggatan/Hamngatan in central Eskilstuna, built 1930–1933 to Paul Hedqvist's design in strict functionalism with the square as its basic motif. The pool hall had seven-storey windows shaped as a standing double square, and the façades were large, plain light-plastered surfaces. The building is now a listed monument and part of Mälardalen University's campus.

The question of a public bath in Eskilstuna was studied from 1917; an invited architectural competition in 1930 was won by Paul Hedqvist with the entry "Gå och bada". The bathhouse opened on 22 January 1933 as Sweden's largest warm bathhouse. In 1985 it was rebuilt and enlarged, becoming the country's first bathhouse with a wave machine. It closed on 13 May 2016 after 83 years, and from 2017 the building was converted into a campus for Mälardalen University, completed in 2020.

The building's name, Vattenpalatset ("Water Palace"), was already in use for the 1933 bath house. In 1985 it became the country's first bath house with an adventure pool and wave machine, promoted with the slogan "Varför åka till Mallorca när man kan bada på Vattenpalatset?" ("Why go to Mallorca when you can swim at Vattenpalatset?"). Eskilstuna Simklubb trained here, and the Gympozz gymnastics club had its premises beneath the adventure pool.

The building stands at the corner of Drottninggatan and Hamngatan in central Eskilstuna, but it no longer houses baths: the pools closed on 13 May 2016. Since 2020 it serves as the Mälardalen University campus, so the former pool hall is seen from outside or through university events, not as a swimming facility.

The building's swimming hall window is a seven-storey-high upright double square, echoing architect Paul Hedqvist's use of the square throughout. The pool room was designed for a 33 by 12 metre basin with seating for 500 spectators and a seven-metre diving tower. The building has been a listed cultural monument since its functionalist design drew national and international attention.