Château D'Eau, Neoclassical fountain in Cachoeira do Sul, Brazil

The Château D'Eau is an eclectic-style water tower and fountain in Cachoeira do Sul, designed in 1925 by engineer Walter Jobim with structural calculations by Antônio de Siqueira. It stands near the Catedral Nossa Senhora da Conceição and the Casarão da 15 de Novembro, forming one of Rio Grande do Sul's most important architectural ensembles. Its sculptures of Neptune and a group of nymphs were made in the workshops of Vicente Friedrichs in Porto Alegre under Giuseppe Gaudenzi.

The fountain was designed in 1925 as part of the city's water distribution system and served a functional purpose for decades. It fell out of active use in the late 20th century but was later restored and granted official cultural heritage protection.

The fountain's sculptures of Neptune and a group of nymphs were carved in the Porto Alegre workshops of Vicente Friedrichs under Giuseppe Gaudenzi, an Italian sculptor living in that city. During a restoration, the water jets that had spouted from the maidens' pitchers since a 1960s modification were removed, bringing the fountain closer to its original look. At the 2012 heritage listing ceremony, young actors from the Colégio Marista Roque theatre group posed as Neptune and two nymphs.

The fountain is located near the church and easily accessible on foot from the city center. The site is open to visitors, who can view and photograph the structure from outside without any restrictions.

The Neptune and nymph sculptures were cast in the Porto Alegre workshops of Vicente Friedrichs under Giuseppe Gaudenzi, an Italian sculptor based in that city. During a restoration, the water jets added to the nymphs' urns in the 1960s were removed, bringing the fountain closer to its original appearance.