Hall of Waters, Historic mineral water resort building and city hall in Excelsior Springs, Missouri, USA

Hall of Waters is a five-story reinforced concrete structure shaped like a T with a distinctive 30-foot (9-meter) aluminum-capped tower rising from its center. The building now serves as Excelsior Springs City Hall and contains a visitor center for guests.

The Hall of Waters was built in 1936–37 as Public Works Administration Project #5252, designed by the firm Keene & Simpson. It was raised on the site of the first spring found in Excelsior Springs in the 1880s, centralizing the city's mineral baths and bottling plant. It was listed on the National Register of Historic Places in 1983 and named one of America's most endangered historic places in 2020.

The Hall of Waters was built to centralize the mineral waters that had drawn visitors to Excelsior Springs since the 1880s, combining public baths with a water bottling plant. Its Art Deco and Depression Modern design made it both a civic landmark and the engine of the town's health-resort economy, supporting hotels such as The Elms Hotel and Spa.

The Hall of Waters stands in downtown Excelsior Springs and serves as City Hall, with a visitor center inside. The building was named one of America's most endangered historic places in 2020, so parts of the interior may be closed while repairs are planned; ask at the visitor center which rooms can be seen.

The Hall of Waters was built as a Public Works Administration project, #5252, in 1936–37 to the designs of Keene & Simpson. Its 30-foot boiler stack tower, faced in cast stone and capped in aluminum, is the detail most visitors miss. In 2020 the National Trust for Historic Preservation listed it among America's most endangered historic places.