Nordmannsturm, Observation tower in Nienstedt, Germany.

Nordmannsturm is a stone observation tower rising 19 meters on the Deister mountain range. The structure provides views northward toward Calenberger Land and southward toward Weserbergland.

The tower was built in 1863 by Hanoverian master mason Constantin Nordmann, using stone blocks from the Teufelskammer quarry on the Deister's southwestern slope. A lightning strike in 1881 almost completely destroyed it, and Nordmann rebuilt it the following year. In 1933 it passed to the Hannoverscher Touristenverein, and a 1998 restoration was funded by Barsinghausen, Bad Münder, the Großraumverband Hannover, the Hameln-Pyrmont district and EU grants.

The tower is owned by the town of Bad Münder, which bought it in 2001 for a symbolic price and acquired the land in 2002. A support association (Förderverein) has since maintained the listed structure, and in 2013 it marked the tower's 150th anniversary. A restaurant at its foot serves visitors during opening hours.

Visitors can climb the tower during posted opening hours, with stairs leading to the viewing platform where windy conditions may occasionally occur. Sturdy footwear is recommended, and caution should be taken on wet surfaces.

The tower's stone blocks were quarried from the Teufelskammer, a quarry on the southwestern slope of the Deister. A lightning strike in 1881 nearly destroyed the tower, and Constantin Nordmann rebuilt it the following year. In 2013 the Förderverein Besucherbergwerk Barsinghausen marked its 150th anniversary.