Chicago Lanmark is a designation of the Mayor of Chicago and the Chicago City Council for historic buildings and other sites in Chicago, Illinois, United States. Listed sites are selected after meeting a combination of criteria, including historical, economic, architectural, artistic, cultural, and social values. Once a site is designated as a landmark, it is subject to the Chicago Landmarks Ordinance, which requires that any alterations beyond routine maintenance, up to and including demolition, must have their permit reviewed by the Landmarks Commission. Many Chicago Landmarks also are listed on the National Register of Historic Places, providing federal tax support for preservation, and some are further designated National Historic Landmarks, providing additional federal oversight.