The purpose of this study is to review, clarify and strengthen the application and assessment of criterion (vii -- contain superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance) in order to improve advice to States Parties in the nomination process and enhance guidance for the IUCN evaluation process. This study conducts a case history of the application of this criterion, with a focus on properties inscribed since 1995, and reviews scholarship in related disciplinary fields. In coordination with ICOMOS, this study also reviews aesthetic considerations in the application of cultural criteria.