Karlstr.21 to my eyes...I can't make out the rest, sorry...
Karlstr. is right and the town is Zinnowitz. (It's on the Island of Usedom in Mecklenburg-Vorpommern.)
thanks for replies. This is very interesting. You can read the surname?
thank you very much!
It seems to me it is Karlstrasse 2/ and some other number. Maybe 6?
Tomorrow I will take better photo from this number