Research into cultural landscapes began before the Second World War with increasing concern about their disappearance. Historical research into shōen and rural engineering, the scientific investigation of geographic features, and studies for urban and countryside planning have since increased. The movement to protect cultural landscapes has also been influenced by the Law Concerning Special Measures for the Preservation of Historical Natural Features in Ancient Cities (1966), the international trend for recognising cultural landscapes under the World Heritage Convention, the designation in 1980 of Mount Hakusan, Mount Ōdaigahara & Mount Ōmine, Shiga Highland and Yakushima as UNESCO Man and the Biosphere Reserves, the designation of Monuments of Japan, and initiatives such as the 100 selected terraced rice fields of Japan. From 2000 to 2003 a study was made to define the concept of cultural landscape and identify their distribution, with 2,311 areas identified in the first phase and 502 selected for the second, 180 being of particular importance.