World War I post cards

I have a bag of pictures and family papers that I'm just starting to go through.  I've barely scratched the surface, but I found these three post cards scattered among the pictures.  They're faded, yellowed, and there's little or no writing on the back to give me any clue of who they belonged to, or why I have them.  They weren't mailed, so there are no stamps, or postmarks.  And, unfortunately, most anyone in my family that might know anything about them, have already passed.

There are no family stories that I can remember hearing about World War I. But the ship, the airplane, and the cemetery will be easy enough to research.  Linking them back to my family, may not be so easy.

I may never know what the importance, if any, of these post cards is, or how they came to be in the sack in the first place.  It's a mystery.

There's a story here somewhere.  If I can't find the truth, I'll make something up -- eventually--because I'm fascinated by these pictures.

This is one of the ways writers get their ideas...