Northumberland Avenue is a street in the City of Westminster, Central London, running from Trafalgar Square in the west to the Thames Embankment in the east. The road was built on the site of Northumberland House, the London home of the Percy family, the Dukes of Northumberland between 1874 and 1876, and on part of the parallel Northumberland Street.
When built, the street was designed for luxury accommodation, including the seven-storey Grand Hotel, the Victoria and the Metropole. The Playhouse Theatre opened in 1882 and become a significant venue in London. From the 1930s onwards, hotels disappeared from Northumberland Avenue and were replaced by offices used by departments of the British Government, including the War Office and Air Ministry, later the Ministry of Defence. The street has been commemorated in the Sherlock Holmes novels including The Hound of the Baskervilles, and is a square on the British Monopoly board.(Wikipedia)