Burg Eggersberg, Medieval castle ruins in Riedenburg, Germany

Burg Eggersberg is a ruined spur castle on the Kirchfelsen, a rock outcrop rising to 440 m above sea level on the northern edge of Obereggersbach, just under 200 m north of Schloss Eggersberg. The surviving walls are mostly from a Baroque chapel built in 1736, which largely collapsed in 1806. A roughly four-metre-high section of bossed ashlar masonry from the early 13th-century bergfried stands at the rear, with lower broken walls curving forward on the left and right, a short flight of rough stone steps at the front left, and a broad, deep semicircular neck ditch. Grass covers the ground between the light gray and beige stone walls, and a line of trees borders the right side.

Burg Eggersberg was built in the 13th century and first recorded in 1326 as "Feste Eggersberg". It belonged to the Bavarian dukes, who pledged it from the late 14th century to Wilhelm den Fraundorfer, Balthasar Muracher, Haimeran von Muggenthaler, Georg von Pappenheim and from 1485 to Graf Jörg von Helfenstein. In 1491 Duke Albrecht IV destroyed it in the Löwlerkrieg; after repairs it was demolished in 1613.

The tall pale wall visible today is the ruin of a Baroque chapel built in 1736 on the castle grounds, replacing the parish church that once stood inside the castle walls. It collapsed largely in 1806. The site is also called Burg- und Kapellenruine, marking the pairing of fortification and chapel.

The ruin stands on the Kirchfelsen, a rock spur about 200 metres north of Schloss Eggersberg at the end of the village lane of Obereggersberg. The ground between the walls is grass-covered and uneven, and a short flight of rough stone steps climbs a low wall segment at the front left. The site lies on a slope above the Altmühltal, so sturdy shoes are useful.

The tall pale wall at the rear is not medieval: it belongs to a Baroque chapel built on the castle grounds in 1736, which largely collapsed in 1806. The older masonry nearby is the bossed ashlar of the former bergfried, begun in the early 13th century and still standing about four metres high.