Christiansburg Castle is one of the most representative Baroque complexes in Thuringia. There is evidence of a castle in Eisenberg on the site of the palace as early as the 12th century. It was of strategic importance due to its location. The castle was rebuilt and extended over the following centuries.

At the end of the 17th century, Duke Christian von Sachsen-Eisenberg chose Eisenberg as his residence and had the existing ensemble of buildings rebuilt to create today's baroque three-winged complex. Only the west wing remains of the medieval castle and the previous Renaissance palace. A special feature is the Castle Church of St. Trinitatis, which the duke had built on the east side of the palace. It is considered the most beautiful baroque church in the state. The palace complex also includes the two-part castle park with a partially preserved arched garden, the classical pavilion in the herb garden, the foundation walls of the uncovered laboratory and the bust of Duke Christian.

Today, the castle houses the district administration office.