| Fort Willem II | |
|---|---|
 Fort Willem II in 1933 | |
  Location within Indonesia | |
| General information | |
| Architectural style | 18th century colonial |
| Town or city | Ungaran |
| Country | Indonesia |
| Coordinates | 7°8′17″S 110°24′18″E / 7.13806°S 110.40500°E |
| Construction started | 1786 |
| Technical details | |
| Structural system | Stone built barracks fort |
Fort Willem II of Ungaran (known locally as Benteng Ungaran or Benteng Diponegoro) is a late 18th-century fort built by the Dutch in Ungaran, Semarang Regency, Central Java, Indonesia. Its main purpose was to control an important trade route between Semarang and Yogyakarta.[1] The fort is the place where Prince Diponegoro was imprisoned while waiting for his judgment in Batavia and further exile to Makassar. The fort is currently used as a dormitory for the families of Indonesian police personnel.