What is the official designation of the building visible from the Morpeth Arms in a manner enabling spying?
Morpeth Arms The Morpeth Arms is a public house at 58 Millbank, in the Pimlico district of London. It was built in 1845 to refresh prison warders serving at the Millbank Penitentiary. It now contains a Spying Room which provides a good view of the headquarters of the Secret Intelligence Service across the river. The building is listed as Grade II and it is now part of the Young's estate.
King's Observatory The King's Observatory (called for many years the Kew Observatory) is a Grade I listed building in Richmond, London. Now a private dwelling, it formerly housed an astronomical and terrestrial magnetic observatory founded by King George III. The architect was Sir William Chambers; his design of the King's Observatory influenced the architecture of two Irish observatories  – Armagh Observatory and Dunsink Observatory near Dublin.