Altendorfer Berg, Mountain summit in Einbeck, Germany

Altendorfer Berg is a 270.8-metre-high elevation of Muschelkalk limestone at the southern end of the Hube ridge, on the eastern edge of Einbeck's town centre in Lower Saxony. Its slopes fall south towards the Ilme and the Leine valley, and the name comes from the deserted village of Altendorf (Oldendorf), after which the parcel is named.

The area served as a Bundeswehr military training site covering more than 120 hectares until the 1980s. When the military withdrew, the land was redesignated as a protected nature reserve.

The Kaiser-Friedrich-Turm is not on the summit but on a side ridge just north of the Altendorfer Berg, at about 280 m. The stone lookout tower was built in 1900 and named after Emperor Friedrich III. Its 130 steps and balustrade have structural defects, so it cannot currently be climbed; a support association founded by Einbeck citizens in 2014 works to preserve it.

Marked walking trails lead to the summit, with parking areas available at Negenborner Weg for easy access. Public buses serve the nearby Paul-Hindemith-Strasse station, offering connections to the mountain and surrounding areas.

The Kaiser-Friedrich-Turm, a stone lookout tower built in 1900 and named after Emperor Friedrich III, stands not on the summit but on a side ridge just north of it, at about 280 metres. It is currently closed because of defects in its 130 steps and balustrade; a support association founded by Einbeck citizens in 2014 works to preserve it.