I took these pictures during a visit at the Oscarsborg Fortress, which is situated on a small island in the narrowest strait of the Oslofjord. Any enemy fleet on it's way to the capital of Norway had to pass Oscarsborg Fortress, not an easy task as the German fleet discovered in April 1940. Oscarsborg Fortress has been open for the public only for a few years now, and is really worth a visit. It is large, even by international standards, and the area is beautiful and filled with interesting objects. There were a lot of guns placed around the fortress. Many of them completely unknown to me, so I would appreciate if anyone could ID them for me.