The Swedish national radio observatory at Onsala, 45 km south of Gothenburg, Sweden, founded in 1955. It is operated by Chalmers University of Technology, Gothenburg. Its main instruments are a 25.6-m antenna, opened in 1964, and a 20-m millimetre-wave telescope in a radome (protective dome), opened in 1976 and upgraded in 1992. A LOFAR station at Onsala was opened in 2011. Onsala Space Observatory is a partner in the Atacama Pathfinder Experiment (APEX).

http://www.chalmers.se/en/centres/oso/Pages/default.aspx Official observatory website.