Kaunilanmaa consists of a dense forest that has remained completely untouched for several decades. The eastern part of the area consists of spruce trees that are over 100 years old. The western part on the other hand is slightly more diverse; in addition to pine, which is the dominant species, the area also features birch, spruce, and aspen. Judging by the age of the pines and the burnt tree stumps, the western part of the area may have suffered a wildfire about 80–90 years ago.

The fact that the forest has been undisturbed for several decades (at least 50 years according to the previous owners) has contributed to the area’s diversity; on the western side there is an abundance of decayed wood and hollow trees, as well as ant nests. In the middle of the forest there is a small undrained peatland area that features a large number of windfalls and decayed trees.

At Kaunilanmaa visitors can enjoy the sound of trees creaking in the wind and encounter a nesting willow tit (Parus montanus) or crested tit (Parus cristatus), both of which have become endangered species due to the loss of old-growth forests.

The Natural Heritage Foundation received a substantial donation earmarked for the purchase.