Tsushima is an island, really a group of islands in the Sea of Japan. Most of the island is rural and a nature reserve. There are distinctive stone roofed buildings which are unlike any found elsewhere in Japan.
This stamp shows a very typical Japanese landscape with cherry blossom and I think that must be Mount Fuji in the background.
These two were on a different postcard..
This is a post for Sunday Stamps, now hosted by Violet Sky at "See it on a Postcard!"