Book Nook in a fireplace that is no longer usable. Very creative use of space. Just make sure to clean that fireplace well before putting any books in there and to seal things to prevent water damage or pests from coming down the chimney.
Meera Sky Garden House by Guz Architects is a beautiful, lush, eco-friendly house built on prime real estate on Sentosa Island, previously known as Palau Blakang Mati, in Singapore. The Meera Sky House truly looks like a garden house set in the sky.
In the Silo? If I ever have land, I'm going to build a few of these for my kids as they become young adults but aren't ready to go into debt for a place of their own. They can go live in a drain pipe out back for awhile.