17 January 1905
The Observatory was founded as the Transvaal Meteorological Department, and was initially meant to be used to watch weather patterns. Astronomer Dr Robert Innes moved from Cape Town to become the first director of the centre. It was officially opened in 1905 and the first telescope was installed in 1906. The Observatory sits on a hill in the suburb of the same name. The land was owned by the Bezuidenhout family before they gave it to the government. South African Agency for Science and Technology Advancement (SAASTA) acquired the Johannesburg Observatory in 2003 and has since refurbished the site to accommodate a multifaceted interactive science awareness facility with a specific focus on astronomy and engineering. The observatory is now open to teachers, learners and members of the public in general. The centre also organizes night tours.
References

Davie L. (2003) ‘Observatory celebrates 100 years’ from Joburg.org [online] Available at: www.joburg.org.za [Accessed on 7 December 2011]|SAASTA ‘Johannesburg Observatory’ from SAASTA [online] Available at: www.saasta.ac.za [Accessed on 7 December 2011]