I received these postcards around 5 years ago.
Numbers 2, 4, 6 9, and 11 are stamps that were attached to the postcards shown with the country name
The postcards and stamp pictures are not great, because I took them myself.
I belong to Postcrossing.com and it's free (except for the stamps and postcards) to send and receive cards.
It's really fun to read the messages and see the cards and stamps from around the world.
The image is Rotterdam, Netherlands.