Kensington Gardens, once the private gardens of Kensington Palace, are among the Royal Parks of London. The gardens are shared by the City of Westminster and the Royal Borough of Kensington and Chelsea and sit immediately to the west of Hyde Park, in western central London. The gardens cover an area of 270 acres. The open spaces of Kensington Gardens, Hyde Park, Green Park, and St. James's Park together form an almost continuous "green lung" in the heart of London. Kensington Gardens and Hyde Park are Grade I listed on the Register of Historic Parks and Gardens.