The Customs House is an historic Sydney landmark located in the city's Circular Quay area. Constructed initially in 1844-1845, the building served as the headquarters of the Customs Service until 1990. Ownership was then transferred from the Commonwealth Government of Australia to the City of Sydney Council in 1994, when it became a venue for exhibitions and private functions. After being refurbished in 2003, it has also become the new home of the City of Sydney Library. The ground floor of the building houses a 4.2m x 9.5m scale model of Sydney's CBD, viewed through a glass floor. The model was built by Modelcraft in 1998 and weighs one tonne. Images of the various versions of the building across its history are also displayed.