Gut Falkenberg, Neoclassical estate in Lürschau, Germany.

Gut Falkenberg is a Neoclassical manor house built 1796–1804 by architect Carl Gottlob Horn for Count Heinrich von Reventlow, on the ruins of the former Wasserburg Alt-Gottorp. The plastered building has nine axes and a two-storey central risalit with a triangular pediment, and a tiled roof. Inside, wall paintings by Giuseppe Anselmo Pellicia survive, including mythological scenes found in 2010 in the garden hall and an adjoining cabinet.

Count Heinrich von Reventlow (1763–1848) bought the area around the old Ruhekrug rest stop at the end of the 18th century and had the Neoclassical manor house built between 1796 and 1804 on the ruins of the Wasserburg Alt-Gottorp, a former bishop's castle abandoned by 1161. In 1851 King Frederick VII of Denmark acquired the estate and converted the house into a small hunting lodge. Since 1971 it has belonged to the von Samson-Himmelstjerna family.

The name Falkenberg (Falcon Mountain) comes from falcons that flew south over the land in autumn and north in spring. The estate lay beside the Ochsenweg, the historic cattle road from Viborg to Hamburg, where traders with their oxen had long rested at the old Ruhekrug station. The wrought-iron gate bearing King Frederick VII's initials F. R. (Fredericus Rex) stands restored in front of the manor house.

Gut Falkenberg lies in the municipality of Lürschau, in the Schleswig-Flensburg district. The old north-south road, the Ochsenweg, once ran between the park and the manor house, cutting through the estate. The manor is privately owned by the von Samson-Himmelstjerna family, who have farmed the land since 1958, so the house and grounds are not open to the public.

The manor's name recalls falcons that flew south over the land in autumn and north in spring. The estate also preserves the fenced grave of a Danish soldier killed during the Deutsch-Dänischer Krieg of 1848–1851, when fighting crossed the north-south road running between park and house.