National Fossil Wood Park, Tiruvakkarai, Geological park in Tiruvakkarai, India.

The National Fossil Wood Park in Tiruvakkarai is a geological heritage site containing over 200 petrified tree trunks scattered across its grounds. The trunks vary in size and some remain in their original positions, giving visitors a direct sense of how the ancient forest once looked.

The fossil trunks lie in Cuddalore sandstone dated to the Miocene–Pliocene, about 20 million years ago, not 200 million. The European naturalist M. Sonneret gave the first detailed account of them in 1781. The park was established in 1940 and notified as a National Geological Monument by the Geological Survey of India in 1951.

Local belief holds that these fossil trunks are the bones of a demon killed by the god Vishnu, which is why the village treats the site as sacred ground. The Tamil name of the village, Tiruvakkarai, is tied to this story. Visitors may notice offerings left among the stones.

The park is easy to explore on foot, with marked paths leading to the main tree trunks. Visitors should wear comfortable shoes and prepare for sunny conditions, as shade is limited throughout the site.

The fossils lie in Cuddalore sandstone dated to the Miocene–Pliocene, about 20 million years ago. Local belief holds that they are the bones of a demon killed by Vishnu. The Tamil Wikipedia notes that only 11 whole trunks and 60 fragments remain of the 180 once counted, the rest taken by people and tourists.