Lancaster House is a mansion on The Mall in the St James's district in the West End of London. Adjacent to The Green Park, it is next to Clarence House and St James's Palace, as much of the site was once part of the palace grounds. Initially planned for Prince Frederick, Duke of York and Albany, it was ultimately completed by the Duke of Sutherland, as an aristocratic townhouse in the early 19th century, and known for its lavish interiors. Gifted to the government in the early 20th century, it houses the government's wine cellars and was home to the London Museum until World War II. Now used for diplomatic receptions and related functions by the Foreign Office, it is a historic Grade I listed building.