No international legal judgment has determined the meaning of the environment’s aesthetic value. But many officials interpret words for international law, including those that must negotiate and administer treaties. Chapter 3 looks to such instances of interpretation as it analyses the meaning of ‘aesthetic’ value in accordance with the Vienna Convention on the Law of Treaties. It considers the meaning of ‘aesthetic’ value as an express term of the conventions on world heritage and biodiversity, and as a term informing the interpretation of the Whaling Convention. Applying doctrinal techniques of treaty interpretation, the chapter argues for understandings of aesthetic value theorised among philosophers of environmental aesthetics. However, the practice of treaty bodies suggests interpretations of aesthetic value that are conflated with natural beauty, cultural value and ethical concerns. The chapter observes that orthodox sources for treaty interpretation are written documents and argues that an examination of visual sources should also be entertained. Images, such as photographs, could provide a rich account of the environment’s aesthetic value in international legal practice.