Jōmon Sugi is a large cryptomeria tree (yakusugi) located on Yakushima, a UNESCO World Heritage Site, in Japan. It is the oldest and largest of nearly 2,000-year-old-growth cryptomeria trees on the island, and is estimated to be between 2,170 and 7,200 years old. Other estimates of the tree's age include "at least 5,000 years", "more than 6,000 years", and "up to 7,000 years old". The tree's name is a reference to the Jōmon period of Japanese prehistory.
Jōmon Sugi is located on the north face of Miyanoura-dake, the highest peak on Yakushima, at an elevation of 1,300 m (4,300 ft). Discovery of the tree in 1968 "sparked moves to protect the forests" of Yakushima and gave rise to the island's tourist industry, which comprises more than half of its economy. Jōmon Sugi is accessible via the Kusugawa Hiking Path (east of Miyanoura) and the Arakawa Trail (starting at the Arakawa Dam), but requires a "four-to-five hour mountain hike" from the nearest road to reach. After the designation of Yakushima as a World Heritage Site in 1993, local officials restricted access to the tree to an observation deck built at a distance of 50 ft (15 m) from the tree.
The tree has a height of 25.3 m (83 ft) and a trunk circumference of 16.2 m (53 ft). It has a volume of approximately 10,000 cu ft (300 m3), making it the largest conifer in Japan. Tree-ring dating conducted by Japanese scientists on the tree's branches indicated that Jōmon Sugi is at least 2,000 years old. In Remarkable Trees of the World (2002), arborist Thomas Pakenham describes Jōmon Sugi as "a grim titan of a tree, rising from the spongy ground more like rock than timber, his vast muscular arms extended above the tangle of young cedars and camphor trees".