The term 'Mundat Forest' refers to two forests that overlie the modern border between Germany and France near Wissembourg, Alsace. The Upper Mundat Forest is a small part of the mountainous Palatinate Forest. The smaller Lower Mundat Forest forms a fraction of the Bienwald in the Upper Rhine valley.
In the Middle Ages the forests were part of the Wissembourg Mundat, the privileged possessions of the abbey of Weissenburg (now Wissembourg), whose abbot was a territorial magnate, a Prince-abbot of the Holy Roman Empire. The unusual term, Mundat, refers to the immunity (emunitas) granted by the royal conveyor of property, which rendered the abbey immune from obligations of service for the grant of vast privileged domains situated within the diocese of Speyer.
The Upper Mundat Forest is an area of roughly 40 square kilometres (15 sq mi) that stretches north and west from the Alsatian town Wissembourg. Its highest point, at 561 metres (1,841 ft), is the Hohe Derst near the hamlet of Reisdorf. The area includes the remains of Guttenberg Castle, c. 1150. It is part of the cross-border UNESCO biosphere reserve Pfälzerwald–Vosges du Nord.
The Lower Mundat Forest is an area of roughly 20 square kilometres (8 sq mi), east of Wissembourg in the plain formed by the Rhine rift. Geographically it is part of the Bienwald. Its highest elevation is 141 metres (463 ft).
The Upper and Lower Mundat Forests together make up the still-forested part of the Mundat, the former possessions of the 7th–16th century monastery and principality at Wissembourg. To distinguish it from the similar but unrelated Mundat at Rouffach further south, it is also known as the Wissembourg Mundat or, confusingly, the Lower Mundat – the Rouffach Mundat being the Upper Mundat.