Großer Kahlenberg, Mountain summit in Saarpfalz-Kreis, Germany

Großer Kahlenberg is the highest summit of the Bliesgau at 401.1 m above sea level, rising in the Saarpfalz-Kreis southeast of Breitfurt. Its crest carries the ground-floor ruin of the Alexanderturm, built of thick red sandstone blocks on a square plan 5 m on each side, with a new spiral staircase and viewing platform added in 2021. Middle Muschelkalk forms the slope, upper Muschelkalk the top.

In 1893 the 26.35-metre Alexanderturm observation tower was completed on the summit, also called Böckweiler Aussichtsturm. It was blown up by Wehrmacht engineers at midnight on 9–10 September 1939, days after the war began. Only the ground-floor ruin of red sandstone blocks remains, with a side length of 5 m; a sandstone plaque above the former entrance names the builder, Baron Alexandre Jacomin de Malespine (1821–1893).

The mountain draws visitors interested in observing wildlife and photographing the natural surroundings of the Bliesgau region. People spend time here exploring the diverse plant and animal species that inhabit the slopes.

No roads lead to the summit; it is reached only on marked hiking trails that also pass the Kahlenberger Hof and Kirchheimer Hof farms. The L 105 runs west of the hill between Breitfurt and Bliesdalheim, the L 103 east through Böckweiler. A spiral staircase built into the ruin in 2021 leads to a viewing platform.

From the top, you can observe the geographical boundaries between different natural regions of western Germany. On especially clear days, you can see how the Bliesgau landscapes transition into the surrounding areas.