In the centre of the Hessian town of Hadamar, Schloss Hadamar shapes the historic townscape; today it houses administrative authorities, while the adjacent economic buildings are used as the town museum and as court premises. The castle church in the east wing has served the Protestant parish of Hadamar since 1791.
The ensemble stands on the left bank of the Elbbach and was built on the foundations of a medieval moated castle. Originally the complex was surrounded by a moat and featured a drawbridge, a double gate and several towers; remains of a monastic apse and vaulted cellars still point to earlier building phases. In its present appearance the Renaissance articulation predominates: a three-storey horseshoe-shaped layout with mullioned-and-transomed windows, cross-gabled dormers and a central staircase that was added onto an older castle tower.
The site’s history goes back to shortly after 1190, when a manor of the Cistercian monastery Eberbach was established here. In 1320 the grounds passed to members of the House of Nassau; after the granting of town rights in 1324 the castle and settlement were incorporated into the town fortifications. In the 15th century a great hall and a chapel were built, and in the following centuries the complex underwent alterations, fire damage and changes of ownership. After a division of inheritance in 1607, under the then territorial ruler an extensive conversion from fortress to representative palace took place: the north and east wings were renewed in the 1610s, the south wing was completed in 1629; work was interrupted by wartime pauses, and later decorative phases followed in the interiors. The original princely line ended in the early 18th century.
In the 19th and 20th centuries the use of the building changed: courts, schools and administrative offices occupied parts of the castle; school and sanitary facilities were added, while the castle garden and subsidiary wings were repeatedly parceled off or demolished. After a period of vacancy the main building was renovated from 1982 to 1988 and repurposed as an administrative centre; since the end of the 20th century various departments of the district and state agencies have been housed here. The town museum opened in the northern service courtyard in 1988; in recent years a nativity-scene museum (2012) and a glass museum (2014) have been added in historic rooms. The castle also has protected status under the Hague Convention for the Protection of Cultural Property in the Event of Armed Conflict.