Deep in the forest between Zwettl and Gross-Gerungs, stands a 7 meter (22 ft) pyramid. The pyramid is made of loosely stacked natural stones, done in a circular layer style like a cake. It is the only known structure of its kind found in central Europe.

The origin and the age of the pyramid are unknown. Some believe it to be a ancient Germanic monument, however this is unlikely as archeological evidence doesn’t support this and there was no known prehistoric or early settlement in this area.

More likely is that the pyramid is of a more modern heritage. In 1747, Leopold Christoph founded the masonic lodge in the area at Rosenau Castle. The pyramid may have served as a signaling station for the secret organization. Ruins of walls have been found nearby and it is possible the pyramid was part of a much larger complex.

The strange ivy covered pyramid has been an official monument since 2001.