The Sankt Andreasberg Observatory is located near the Rehberg on the premises of the Internationale Haus Sonnenberg, an international educational facility.

[1][6][7] The air in an altitude of 710 metres[3] is especially low on turbidity and since the Harz Nature Park is far away from big cities, there is far less light pollution there then in other parts of northern Germany.

However, due to environmental protection constraints, it was decided in July 2013 to rent a building of the Internationale Haus Sonnenberg, about 1 km north of the originally designated site, and to repurpose it as an observatory.

[3] The outdoor area includes five telescope mounts of different heights, featuring power outlets and data transmission facilities.

Another reflecting telescope, featuring a primary mirror of 400 mm diameter (16″ f/8 Hypergraph[10]) and a computer aided mount of type Knopf MK70S were first used during the STATT 2015 (August 13–16, 2015).

Therefore, the building is equipped with sufficiently wide doors, step free access ways and ramps for people with mobility constraints, as well as handrails with Braille inscriptions.

Talking telescopes enable visually impaired people to experience their own and astronomical objects' spatial orientation.

A Children's and Youth's academy for Astronomy is planned to be established in cooperation with the Internationale Haus Sonnenberg, focusing on STEM fields and Environmental studies.