OB 6.5cm Geschütz (norw.) is a Norwegian military bunker located near Tønsberg, Vestfold, Norway. The designation 'OB' stands for 'Objektbunker' (object bunker), and 'Geschütz' refers to a gun emplacement. This structure was part of Norway's coastal defense system, likely built to house a 6.5cm artillery piece for protecting the coastline.
The bunker's location near Tønsberg, one of Norway's oldest towns, suggests it was strategically positioned to defend important maritime approaches in the Oslofjord region.