[3] Today, the observatory forms a part of Green Templeton College of the University of Oxford.

[4] It was built on the suggestion of the astronomer Thomas Hornsby, who was occupying the Savilian Chair of Astronomy, following his observation of the notable transit of Venus across the sun's disc in 1769 from a room in the nearby Radcliffe Infirmary.

Because of the viewing conditions, weather, urban development and light pollution at Oxford, the observatory moved to South Africa in 1939.

Eventually that site, in Pretoria, also became untenable and the facility was combined with others into the South African Astronomical Observatory (SAAO) in the 1970s.

[4] The original instruments are now in the Museum of the History of Science, Oxford, except for the Radcliffe 18/24-inch Twin Refractor telescope, which was transferred to the University of London Observatory.