This district is defined as the southern part of the Royal Borough of Kensington and Chelsea ( RBK & C ), from the Thames in the south to Kensington High Street in the north, also taking in Hyde Park in the east and the area around Kensington Olympia in the west. It includes the area south of the Royal Parks commonly known as High Street Kensington and South Kensington west to Earl's Court and Olympia and south to West Brompton , Sloane Square and Chelsea . Hyde Park and Kensington Gardens combine to form the largest green space in metropolitan London and provide a real oasis in the heart of this vast city. South Kensington hosts four of London's largest and finest museums, as well as its oldest and arguably most famous concert hall, and is home to the venerable Imperial College. High Street Kensington leads to a long line of shops and department stores, offering a less hectic version of Oxford Street as well very upmarket stores in Knightsbridge . Sloane Street connects Knightsbridge to Chelsea via Sloane Square and is lined with luxury brand boutiques. Chelsea is an extensive riverside area of London that extends broadly from Sloane Square in the east to the World's End pub in the west and down to the River Thames. The King's Road marks the main thoroughfare of Chelsea.The district contains the second largest number of American immigrants in the United Kingdom, many of whom work in the financial sector in The City, while others are connected to institutions such as the American International University, which has a campus just off High Street Kensington. Many local shops, from convenience stores to supermarkets, stock American products in their ethnic food sections. South Kensington is sometimes called the "21st arrondissement" due to the number of French expatriates living there; enough to technically make London the sixth largest French city. The community results in many French cafés, delicatessens and other businesses in the area. Knightsbridge is known for both its Russian and Arab populations, with the accompanying restaurants and institutions they bring.The whole of the district contains some of the most expensive residential property in the world but is a little more downmarket towards its western edges.