Wasserwerk Hinkelstein, Historic waterworks in Frankfurt, Germany.

Wasserwerk Hinkelstein is a groundwater extraction facility in Frankfurt's municipal forest, built 1890–1893 under William Heerlein Lindley and in operation since 1894. Of the original complex only the domed machine house of red Main sandstone survives, a rotunda 12 metres across with ten buttresses and neo-Romanesque windows. Ten wells 66 to 143 metres deep yield about 18,000 cubic metres daily.

The facility was built from 1890 to 1893 under city architect William Heerlein Lindley and opened in 1894 as the third groundwater source in Frankfurt's municipal forest. The construction responded to the city's growing need for reliable drinking water supply.

The name Hinkelstein comes from an old field name referring to a large menhir at the western end of the Hinkelsteinschneise, south of the Main railway. In the early 19th century the stone was broken up and its pieces used as boundary markers in the city forest. The forest house Hinkelstein was built in 1731 to protect the area, and the surrounding Hinkelsteinrauschen was one of five districts of the Frankfurt city forest.

The site is located in Frankfurt's municipal forest and operates as an active technical facility working around the clock. Access to the grounds may be restricted since it serves as working infrastructure rather than a public venue.

The name Hinkelstein comes from a large prehistoric stone monument whose pieces were scattered as boundary markers throughout the forest. This connection between an ancient monument and modern infrastructure often surprises visitors exploring the site.