In 2011, the park was added to the Ancient and Primeval Beech Forests of the Carpathians and Other Regions of Europe World Heritage Site because of its testimony to the ecological history of the beech tree and the dynamics of forests in Europe since the Last Glacial Period.

The national park the southern part of the roughly 160 km2 (62 sq mi) Hainich, the largest contiguous deciduous forest in Germany.

Some are found nowhere else in Thuringia or are extremely rare in Germany as a whole, and their protection is a responsibility recognized by the National Park.

European beech dominates the forest communities, with additional populations of ash trees, hornbeams, limes, and maples.

The goal of Hainich National Park is to restore a large section of central European forest to its primordial state.