Mahnmal der Deutschen Einheit, Memorial stele in Mainz, Germany

The Mahnmal der Deutschen Einheit is a 3.44-metre-high rectangular concrete block, cast by Paul Sauer from a design by Albert Karl Spelthahn, standing on the Fischtorplatz in Mainz. It is split into three vertical sections and bears the inscription 'Deutschland ist unteilbar'. The narrow side lists German city names from east of the Oder-Neisse and from the former GDR.

The memorial was inaugurated on June 16, 1961, and references the East German uprising of June 17, 1953. It symbolizes Germany's division during the Cold War and the territorial changes that followed.

The monument displays names of German cities that came under Polish or Soviet administration after World War II. Visitors can read the engraved message and understand how deeply the division reshaped Germany's urban landscape.

The memorial stands on the Fischtorplatz in Mainz's old town, a public square rather than a fenced site, so it can be viewed at any time. The concrete block is 3.44 metres high and carries its inscription on the narrow side, where the city names are also engraved. A surface coating applied by 1997 protects the stone from graffiti; an information stele beside it explains the monument's purpose.

The concrete block is 3.44 metres high and was cast by Paul Sauer from Albert Karl Spelthahn's design; Spelthahn, a Baurat in the Mainz building office, presented the triple-split form in July 1960. Since at least 1997 a surface coating has protected the stone against graffiti.