The Finnish Natural Heritage Foundation acquired Harjava, an area of 6,3 hectares in Kalvola, Hämeenlinna, in June 2013. The centre of this triangular area is made up of meadows with small forest-covered islets, all surrounded by a forest that has remained intact for a long time.
The forests close to the edges are dominated by spruces. There is some decayed wood appearing, too, especially in the forest of the southern part. The forests that cover the small islets are made up of deciduous trees of various types: birches, grey alders, rowans, goat willows, and bird cherries.
The vegetation is mainly made up of species typical for fresh heath forests, but there is also some Alpine currant and mezereon appearing, too, close to the north edge and the quagmire, which tells something positive about the amount of nutrients contained in the soil there.
Harjava also provides a home for a brook that flows through the area in its natural bed.
Only a few hundred metres north of Harjava, by Lake Äimäjärvi, there is an area called Kalliomaa, which is significant on a nationwide scale for the groves placed under protection there. There is a lot of common hazel appearing between the two areas, having spread even in the immediate vicinity of the Harjava area.
Harjava is the 39th conservation area of the foundation and the ninth one in the Häme region.