Royal Observatory Flamsteed House

The Royal Observatory Flamsteed House, built in 1675-6 and attributed to Sir Christopher Wren, is a Grade I listed building located in Greenwich Park, SE10. The main north front features two storeys with a three-window centre flanked by square, three-storey angle towers. It is constructed of red brick with white stone quoins on both the towers and the main building. The first floor is notably tall, with a projecting cornice and a balustrade situated between the towers. A long, plain central window is set within a chamfered stone architrave, complemented by a wrought iron balcony. The side windows are framed in moulded, shouldered architraves, and there is a stone string at the first-floor level. The ground floor has seven windows, and the parapet with stone coping features a scrolled ramped inner section that rises almost to the cornice of the main block. The ground floor windows have moulded architraves, and there is a door on the left that opens to a walled terrace, which is blocked at either end by two-storey, one-window 18th-century pavilions styled similarly and topped with domes.

The rear elevation showcases a large canted bay with a coved and moulded cornice and a balustraded parapet, while a 19th-century brick extension obscures the ground floor, leaving only the first floor visible. The entrance is located on the east side, at the right angle, and features a porch with a roof that slopes up to the front parapet. The side and rear windows are long casements set in shouldered, moulded stone architraves. Beneath the east window is a plaque framed in richly carved baroque stone, complete with a serpentine open pediment, which bears a Latin inscription stating that Charles II founded the observatory in 1676.

Inside, a staircase with barley-sugar twist columns leads to the octagon room, which contains historic portraits, telescopes, and clocks. The room features a coved, octagonal ceiling with a decorative border, and a moulded and coved cornice adorned with garlands in high relief and royal ciphers. A later staircase descends to the rear extension, which is now arranged as a museum of historic astronomical instruments.