Freudenkoppe, Medieval castle ruin in Daun, Germany.

Freudenkoppe is the ruin of a hilltop castle on the Nerother Kopf, a basalt cone about 5.5 km west of Daun. Its nearly square keep (8.40 by 8.60 m) stands in the eastern half of the courtyard within a trapezoidal ring wall, with remains of the former castle house on the southern slope and a dry moat on three sides.

King John of Bohemia built the castle between 1337 and 1340 to strengthen his control over the region. Within a decade it passed to Baldwin of Luxembourg in 1346, marking a shift in power over this strategic location.

The name Freudenkoppe derives from the medieval castle name castrum Froudenkube, recorded in 1340 under King John of Bohemia. The site lies on the Nerother Kopf, a basalt cone about 5.5 km west of Daun, and marked the northeast border of the County of Luxembourg when it was built. Nearby stands the Mühlsteinhöhle, a millstone cave.

The ruin lies on the 652 m Nerother Kopf basalt cone, about 5.5 km west of Daun and 1 km southeast of Neroth. The surviving walls were consolidated in 1984/85; the dry ditch on three sides and the south-slope wall remnants are best seen on foot. The nearby Mühlsteinhöhle is a separate stop.

The Mühlsteinhöhle, a millstone cave, lies close to the ruin; the two are separate sites, and the sources record no quarrying beneath the castle walls. The castle itself was first mentioned in 1337 and last in 1460, after which it was probably abandoned and fell into decay.