Grachtengordel West lies alongside four main canals (Singel, Herengracht, Keizersgracht and Prinsengracht) and is marked as UNESCO world cultural heritage. The area defines itself by its broad canals and big residences. The Grachtengordel has many historical sights, including the Anne Frank house, the Grachtenhuis, The Bible museum and House Marseille. Inside the area lies the well know nine streets (9 straatjes) one of the most important shopping areas of Amsterdam. The primary functions of this area of Amsterdam are living and working.