Small Space Secrets: Swap Your Bookcases for Wall Mounted Shelving. Here's a creative shelving arrangement that uses a deeper shelf at bottom to create a sort of bench. The bench can serve as extra seating for parties, or as a display space.
Floating bookshelves, these are bookshelves I like. Looks like you could do this with an IKEA kitchen wall cabinet minus door and turned horizontal to mount. IDEA for narrow wall next to our kitchen wall