Photo of Soldier (maybe in Norway) - Opinion please

[herrzark]

I found this photo.In the back it is writing something.Can not undestand.Need translation and opinio please about the photo. Thank you. Had already posted in my collection thread
(my really small collectiion) Thank you

[HPL2008]

The text translates as:

"On guard
in front of the Fortress Oscarsborg
cordial greetings
Your brother
Karl.
Norway, 5 Jan. 1942"

Oscarsborg is a Norwegian coastal fortress. See: Oscarsborg Fortress - Wikipedia, the free encyclopedia

[herrzark]

thanks for the help