PH: Things That Go Together #4

Thanks to @user6937 for the idea for this swap.

Send 2 pairs of postcards (so a total of 4 cards) that go together.

For example:
Boat and lighthouse or water
Bird and a tree
Library and a book
Adult duck and a baby duck
Map and a car or plane
Royalty and a castle or crown
Etc.

Please send the 4 postcards in an envelope. Postcards should be unwritten and unstamped. They should be store bought only and of good quality. (No handmade/freebie/ad/zazzle). Let your partner know which pcs go together and why.

Please do not use post-it notes on the postcards. I have had a few people tell me that some of them leave marks, therefore ruining the postcard!