Fredriksten is a fortress in the city of Halden in Norway.
| Fredriksten Fortress | |
|---|---|
Fredriksten festning | |
| Halden, Norway | |
 Fredriksten fortress, Halden, Norway - seen from the city's harbor | |
| Site information | |
| Controlled by |  Norway |
| Site history | |
| Built | 17th century |
| In use | 17th century-1905 (fort) - today (military installation) |
| Battles/wars | Swedish invasion 1658 Swedish invasion 1659 Swedish invasion 1660 Swedish invasion 1716 Swedish invasion 1718 Swedish invasion 1814 |