Circular Quay is also the home of Sydney's Museum of Contemporary Art and the City of Sydney Library in the heritage-listed Customs House. Sydney Writers Walk a series of plaques commemorating writers with some connection to Sydney was installed in the footpath along Circular Quay in 1991. In autumn 2006, the largest open-air art exhibition ever in Australia took place on Circular Quay: Over 7 weeks the Berlin Buddy Bears visited Sydney. Each bear represented a member-country of the United Nations, symbolizing the universal principles of peace, freedom and friendship.