Burg Naumburg, Medieval castle in Gladenbach, Germany

Burg Naumburg is an abandoned hilltop castle on the Lammerich, a 356.8 m peak above the Salzböde southwest of Gladenbach. Its oval rampart runs about 50 m north-south and 25 m east-west, with a nearly complete moat and outer wall. An inner wall is assumed, and a southern entrance is still visible as an embankment in the ditch.

Landgravine Sophie of Hesse, not Sophie of Brabant, had the Nauwe Borg built around 1249 after Blankenstein Castle opposite was destroyed. It served as a Hessian counter-castle to the Mainz-held Offenhausen in the Salzböde valley. It was last mentioned in the early 16th century; after 1350 Neu-Dernbach Castle probably took over its role as border fortress.

The name Nauwe Borg, recorded around 1249, means "new castle", distinguishing it from the older Blankenstein opposite. It served as a Hessian counter-fortress against the archbishopric of Mainz's Offenhausen castle in the Salzböde valley, since Blankenstein could not watch that valley. Last mentioned in the early 16th century, it later lost its border role to Neu-Dernbach castle after 1350.

The ruins sit on wooded, hilly terrain, so sturdy footwear and basic fitness are helpful for visiting. It is best explored on foot, allowing time to carefully examine the remaining walls and structures.

The south side is thought to have held the entrance, still visible today as a mound of earth across the moat. Historian Wolfgang Becker, who came from the Salzböde valley and studied the site, placed the hall building (Palas) in the southern part, protected by its own now shallow rampart, and assigned roughly ten-by-ten-metre foundation remains in the north to a bergfried.