The Petrified Forest is located east of Neapolis, between Aghio Nikolao and Cape Maleas. Next to the sea, one can see trunks of palm trees that turned to stone as their soft tissue was replaced by minerals.
According to Wikipedia, "Petrified wood (from the Greek root petro meaning 'rock' or 'stone'; literally 'wood turned into stone') is the name given to a special type of fossilized remains of terrestril vegetation. It is the result of a tree having turned completely into stone by the process of permineralization. All the organic materials have been replaced with minerals (mostly a silicate, such as quartz), while retaining the original structure of the wood. Unlike other types of fossils which are typically impressions or compressions, petrified wood is a three-dimensional representation of the original organic material. The petrifaction process occurs underground, when wood becomes buried under sediment and is initially preserved due to a lack of oxygen which inhibits aerobic decomposition. Mineral-laden water flowing through the sediment deposits minerals in the plant's cells; as the plant's lignin and cellulose decay, a stone mould forms in its place. In general, wood takes less than 100 years to petrify. The organic matter needs to become petrified before it decomposes completely. A forest where the wood has petrified becomes known as a Petrified Forest."