Sibelius Forest is a nature reserve of approximately 100 hectares established in 2018 east of Lake Aulangonjärvi. The area has an aging natural forest, heath forest and groves. The cliffs of Levonkallio and Kärmeskallio have spectacular views over Lake Aulangonjärvi on to the Aulanko nature reserve and the observation tower. Sibelius Forest is home to many different species of birds and animals, including tawny owls, ural owls and flying squirrels.
Sibelius Forest is named after the composer Jean Sibelius, who has wandered in these forests and observed the nature. Sibelius got inspiration for his compositions from nature. Through the Sibelius Forest there is a nature trail with eight different information boards that tell about the nature of the area and the relation between Sibelius and nature. The Sibelius Forest is part of a hiking trail around Lake Aulangonjärvi.