Borge is a medium-sized crag in Fredrikstad, consisting mostly of natural lines. The rock is granite, with sections containing large quartz and feldspar crystals; this gives the rock a somewhat brittle quality in places. The cliff sits open and west-facing above farmland, making it a good afternoon crag in spring and autumn, catching the sun's warmth well into the evening on clear days.
The climbing offers technical individual cruxes and varied steepness.
The Main Wall (Hovedveggen) is the largest sector at Borge, with routes up to 30 meters. The North Wall (Nordveggen) lies 150 meters beyond the Main Wall; both the North Wall and Linddalen have routes up to 15 meters.
Routes not to be missed on a visit include Flaggermusrisset, Oppvind, Bange Anelser, and Arkaden.
Local climbers made occasional visits to the crag in the late 1980s. Some aid climbing was done during this period (Bange Anelser), and a couple of top anchors were placed, but all free ascents at Borge are of more recent date.
The site is a protected cultural heritage area, registered as an old bygdeborg. Bygdeborger are primitive fortifications found on steep, defensible hilltops throughout Norway, generally dated to the Roman and Migration periods (roughly 0–600 AD) and traditionally interpreted as refuges or lookout posts in times of unrest. Østfold has one of the highest concentrations of registered bygdeborger in the country.
Because of this protected status, bolted sport routes are not an option here. A small number of bolts have been placed over the years, but efforts have been made to keep these to a minimum so as not to disfigure the surroundings.
