More specifically, the playground of the junior school has been converted into a park of petrified tree trunks, while a relatively spacious room inside the school has a display of marine and animal fossils. The tree trunks, 5–10 m long and 40–80 cm in diameter, come from the Nostimo Petrified Forest, which consists chiefly in tropical and subtropical plants. The forest grew in deltaic alluvial deposits of the prehistoric Sea of Tethys, which washed the wider area of Kastoria. The fossilised trees are approximately 15,000,000–20,000,000 years old and in excellent condition. Most of them are palms.
The marine fossils consist in starfish, conches, sea-urchins, whelks, oysters, mussels, shells, and other marine fossils that survive in near perfect condition. The most significant of the animal fossils are the jagged jaw (complete with teeth) of a man-eating shark that was 20–25 m long, and the 3,500,000-year-old tooth of an Anancus arvenensis, a mastodon that was an ancestor of the elephant and has been recognised here for the first time in the wider area of Western Macedonia. The mastodon which lived in this area was about the same size as a modern elephant, but had longer tusks. Also displayed are some Neolithic tools (from the 4th millennium bc), a fishing weight, and a blade for harvesting crops.