Hoher Hagen, Volcanic mountain summit in Dransfeld, Germany

Hoher Hagen is a 480-metre volcanic hill in the Dransfeld Municipal Forest, about halfway between Göttingen and Hann. Münden in southern Lower Saxony. Its summit carries the 51-metre Gauß Tower, a concrete observation tower with a restaurant and a lift to the viewing platform. The hill is the eroded remnant of a volcanic vent; the surrounding crags include the Opfersteine, blocks of quartzite left from older sands.

In the 19th century, the mathematician Carl Friedrich Gauss used this peak as a surveying point for his geodetic work across the region. The concrete tower was built in 1964 and named after him in recognition of that work.

The summit's name Hoher Hagen refers to the hill itself, while the tower honours Carl Friedrich Gauss, who visited in 1801 to study the basalt and whose surveying work is tied to the peak. The first geological publication on the hill appeared in 1785, when Göttingen geologists treated it as their local study mountain.

The summit is reached on foot via marked trails through the Dransfeld Municipal Forest; drivers can park near the Gauß Tower. The tower has an elevator to the viewing platform, and the restaurant inside serves hikers. The platform is exposed, so bring windproof clothing and check the weather before setting out.

The mountain is made of basalt, which points to volcanic activity in a part of Germany where this is rarely expected. The tower platform sits well above the natural summit level, which adds considerably to how far you can see across the surrounding hills.