Langenberg, Mountain summit in Olsberg, Germany

Langenberg is a summit of 843.2 metres in the Rothaargebirge range, on the border between North Rhine-Westphalia and Hesse, about 10 metres southwest of the state border. Its rounded top is largely wooded, with a high-heath landscape opening to the east. A wooden summit cross stands there, with small stones placed along its crossbar and a plaque set in a stone mound at its base.

A wooden summit cross has stood on the Langenberg since 2010, near a marker stone whose metal plate reads "Langenberg 843 m über N.N. – höchster Berg in NRW". About 15 metres southeast of the summit, roughly 20 metres southwest of the Hesse border, surveyors set a triangulation point of the German Primary Triangulation Network. The Rothaarsteig and Uplandsteig long-distance trails pass a few metres east of the summit, crossing an old boundary stone.

The Rothaarsteig hiking route passes near this summit, where a marker shows its importance as the highest point in North Rhine-Westphalia. Hikers often use the location as a reference point on longer journeys through the area.

No roads lead to the summit; the nearest access is via residential streets in Niedersfeld and Hoppern. The Rothaarsteig and Uplandsteig long-distance trails pass a few metres east of the top, crossing a historic boundary stone, and the Winterberger Hochtour reaches the mountain via the Oberer and Unterer Burbecker Platz path junctions to the south.

A metal plate on a marker stone about 12 metres southeast of the summit reads "Langenberg 843 m über N.N. – höchster Berg in NRW". The wooden summit cross beside it was erected in 2010, and a trigonometric point of the German main triangulation network lies roughly 15 metres southeast of the top.