A 20-million-year-old fossilized subtropical forest preserved by volcanic ash on the western edge of Lesbos.
Lesvos Petrified Forest
The Lesvos Petrified Forest is one of the largest petrified wood forests in the world, located on the western part of the Greek island of Lesbos in the north Aegean. It preserves the remains of a dense subtropical forest that was overwhelmed by massive volcanic eruptions roughly 17 to 20 million years ago, during the early Miocene, when thick layers of lava, pyroclastic material, and ash buried the trees and isolated their organic matter from the atmosphere.
Over millions of years, silica-rich hydrothermal solutions gradually replaced the wood tissue molecule by molecule, producing trunks in which growth rings, bark texture, root systems, and even color variations caused by iron, copper, and manganese oxides are still visible today. The fossilized trunks, including rare upright specimens and the largest known coniferous trunk of more than 20 meters, are scattered across a broad area of western Lesbos, with the densest concentrations enclosed by the villages of Sigri, Eressos, and Antissa.
The site is a protected natural monument and a central component of the Lesvos Geopark, recognized internationally as an IUGS Geological Heritage Site and included on UNESCO's Tentative List of World Heritage Sites. It is visited through a network of protected parks, walking trails, and a dedicated Natural History Museum in Sigri.