A large colour hanging plan, on paper lined with cloth attached to wooden hang-rails on each end, titled 'Plan of the buildings and grounds of the Royal Observatory Greenwich', April, 1858, drawn under the direction of G.R. Airy, Astronomer Royal. Scale: 1 inch: 10 feet. A note adds that levels were taken in 1869. Added in to this are copies (in blue) of two earlier plans: a 'Plan of the Royal Observatory Greenwich from a drawing made by Flamsteed', MDCLXXVI, with annotations in Latin, and a 'Plan of the Royal Observatory, Greenwich, in 1788, from the "Account of the Trigonometrical Survey", Vol. I', scale: 1 inch: 10 feet. The main (colour) plan also has two small foldout overlays which can be lifted to reveal further details of the rooms/buildings beneath.