This astronomical facility has been in existence in Herzberg since 1965. The institution was named after Alexei Leonov to commemorate his achievements in space and science. It is the oldest of its kind in the state of Brandenburg, but is equipped with modern equipment. It provides so many opportunities for transporting visitors into the magnificent world of the stars. It houses a Zeiss projector under the roof of an 8-metre dome, capable of displaying the starry sky at any location and at any time. Several additional projectors, a modern sound system and large-scale video projectors, as well as an impressive slide-dissolving technology, extend the presentation options. The planetarium delivers a varied programme for children and adults all year round, as well as public observation dates.