The Kellerwald is a low mountain range reaching heights of up to 675 m in the western part of northern Hesse, Germany.

Geologically the Kellerwald, made up mainly of palaeozoic rocks, belongs to the Rhenish Slate Mountains.

Scenically, however, it is also grouped as a separate entity with the Hessian Basin, because the rivers Eder and Itter form a natural boundary.

Further Special Areas of Conservation are, among others, the oak forests on the steep slopes at the Edersee, the aforesaid Keller in the southern part of the nature park and the Urff, a linear Special Area of Conservation from the source to the river's mouth into the Schwalm.

The conservation efforts have yielded, perhaps most importantly, one of Central Europe's last contiguous broadleaf forests of international grade.

Since the 19th century, the northern part of the Kellerwald (since 2004, the Kellerwald-Edersee National Park), as hunting woods for the Princes of Waldeck, has been surrounded by gates.

The main tree here is the beech, which is predominant here in acidic-soil (shale, greywacke, quartzite) woodrush-beech forest.

In cool and damp stream dales grows the rare, highly poisonous common monkshood.

In light beech and oak forests with limy subsoil is found the martagon lily.

In the Kellerwald, parts of which are also a Special Protection Area (for birds), a number of bird species still or once again breed, among them the black stork, the common raven, six kinds of woodpecker (among them the rare middle spotted woodpecker and the grey-headed woodpecker), the black and the red kite (which here reach their highest population density anywhere in Hesse), the peregrine falcon, the Tengmalm's owl, the honey buzzard, the Eurasian eagle owl and the great grey shrike.

In the area that is now the national park, the first raccoons, whose natural habitat is in North America, were released into the wild in Germany on 12 April 1934 by Wilhelm Sittich Freiherr von Berlepsch (1881–1948; "Freiherr" is a title, roughly equivalent to "Baron")[2].