Link to http://www.nhb.gov.sg/NHBPortal/Places/Sites&Monuments/NationalMonuments

The Preservation of Sites & Monuments (PSM) is the national authority that advises on the preservation of nationally significant sites and monuments in Singapore. It is guided by the Preservation of Monuments Act to provide "for the preservation and protection of National Monuments". The PSM traces its roots back to January 1971 as the Preservation of Monuments Board. It was then a statutory board under the Ministry of National Development who was responsible for identifying monuments that are worthy of preservation, based on the criteria that they are of historic, cultural, traditional, archaeological, architectural, artistic or symbolic significance and national importance.