Passage: The Tropical Rainforest Heritage of Sumatra site was inscribed as a UNESCO World Heritage site in 2004. It comprises three Indonesian national parks on the island of Sumatra: Gunung Leuser National Park, Kerinci Seblat National Park and the Bukit Barisan Selatan National Park. The site is listed under Criteria vii - outstanding scenic beauty; ix- an outstanding example representing significant on-going ecological and biological processes; and x- contains the most important and significant natural habitats for in-situ conservation. The Tropical Rainforest Heritage of Sumatra has been placed on the Danger List since 2011 to help overcome threats posed by poaching, illegal logging, agricultural encroachment, and plans to build roads through the site.

Question: What is the name of the organization that deems nature areas as World Heritage sites?
UNESCO