Burg Lülsdorf, Medieval castle in Niederkassel, Germany.

Burg Lülsdorf is a castle in the Lülsdorf district of Niederkassel, North Rhine-Westphalia, and appears in the town's coat of arms. Built in the 12th and 13th centuries, it was rebuilt after 1949 following repeated destruction; its round bergfried lost its roof when lightning struck in 1885.

Burg Lülsdorf was built in the 12th and 13th centuries as the seat of the Lords of Lülsdorf. In 1380 the Vogtei of Lülsdorf passed to the Duchy of Berg, and around 1530 it became the seat of the Amt Löwenberg. In 1446 the Amt Lülsdorf was formed with the parishes of Lülsdorf, Volberg, Mondorf and Bergheim. In 1642 the castle was granted as a fief to Field Marshal Peter Melander von Holzappel.

The fortress displays features typical of Rhine Valley castle construction with its characteristic stone walls and defensive passages. Visitors can still observe the building style that was common for medieval strongholds along this river stretch.

The castle stands in the Lülsdorf district of Niederkassel, southeast of Cologne. It is a private building and not open to visitors; the grounds and exterior can be viewed from the surrounding streets. The site is best reached by car or regional bus, and the terrain around the castle is uneven.

From the fortress one can see across the entire Rhine valley, and its location clearly shows why this spot was chosen for medieval control of the region. This view makes the site's strategic importance obvious even today.