14. Green Templeton

The entrance into the single-storey east wing of the Radcliffe Observatory on the south side of the building. The eighteenth-century Grade I listed Observatory, which dominates the three-acre site of Green Templeton College, was built at the suggestion of Dr Thomas Hornsby, the Savilian Professor of Astronomy, after he had used a room in the nearby Radcliffe Infirmary to observe the transit of Venus across the sun's disc in 1769.

The Observatory was built with funds from the trustees of Dr John Radcliffe, whose estate also financed the Radcliffe Camera, the Radcliffe Infirmary and a new quad for University College. Building began in 1772 to plans by the architect Henry Keene, but was completed to a different design by James Wyatt.

The east wing of the Observatory contained the most important scientific instruments for observing the heavens: a transit instrument (a revolving telescope); two mural quadrants, one facing north and the other south; and a 12-foot zenith sector (a long telescope fixed to the wall and pointing out of the roof). These were needed to measure the position and movement of stars and planets, mainly for the value of assisting navigation.