51°30′35.2″N 0°9′19.7″W / 51.509778°N 0.155472°W
Grosvenor House was one of the largest townhouses in London, home of the Grosvenor family (the family of the Dukes of Westminster) for more than a century. Their original London residence was on Millbank, but after the family had developed their Mayfair estates, they moved to Park Lane to build a house worthy of their wealth, status and influence in the 19th century. The house gave its name to Upper Grosvenor Street and Grosvenor Square.
The house was requisitioned during the First World War, and was sold and demolished in the 1920s. The Grosvenor House Hotel was built on its site.