 Owners may object to the nomination of the property as a NHL; when this is the case the Secretary of the Interior can only designate a site as eligible for designation.NHLs are also included on the National Register of Historic Places (NRHP), which are historic properties that the National Park Service deems to be worthy of preservation.The primary difference between a NHL and a NRHP listing is that the NHLs are determined to have particular national significance, while other NRHP properties may be deemed significant at the local or state level.