Fredriksten Fortress is the most conspicuous part of the town´s scenery where it looms proudly above the town and gives Halden its characteristic appearance.
The fortress was constructed on two parallel ridges. On the north ridge the walls extend from the Dronningens bastion at the west end to Prince Christian's bastion at the east. The south ridge is fortified with Prins Georgs bastion and the main Overkongen bastion on the hill's highest point. Between these two ridges lies the citadel with a number of interesting old buildings. Beyond the citadel the Borgerskansen faces west, overlooking the town from the hillside.
In addition there are three outlying fortifications facing south and east: Gyldenløve, Stortårnet and Overberget. There are a number of monuments at Fredriksten, including one that marks the spot where the Swedish King Karl Xll was shot during the siege of 1718. There are also several museums at the fortress with extensive collections of historical military and civilian objects Fredriksten is an imposing structure with a total wall surface of 2.000 m2 Exploring its ramparts and bastions, storehouses, powderhouses and deep, mysterious passageways is an unforgettable experience. The fortress, which has been preserved as if it were a park, is a picturesque and idyllic spot.