In the United States, the concept of a "little red schoolhouse" is a stirring one, and historic one-room schoolhouses have widely been preserved and are celebrated as symbols of frontier values and of local and national development. When necessary, the schools were enlarged or replaced with two-room schools. More than 200 are listed on the U.S. National Register of Historic Places. In Norway, by contrast, one-room schools were viewed more as impositions upon conservative farming areas, and, while a number survive in open-air museums, not a single one is listed on the Norwegian equivalent to the NRHP.