Idea for when we put french door in dining room. Ikea Shelves Into Built-in Bookcases :: I really love this. You could turn any room into a library with this idea. And you don't need ikea for it, either.
Simple built-in to create a mudroom and/or storage anywhere from an entry, to kids room or in a laundry room by adding shelves or a deeper bench for sitting. Put drawers under bench or have the seat lift up to store things.
Gabion stone wall at Maleny House in Australia. Designed by Bark Design Architects. This could be great if you left space in the top for a planter or planted right into the sides with moss, air plants, or tiny hidden sculptures.