Sometimes bookshelves are built into staircases; Adam Jirkal, Jerry Koza and Tomáš Kalhous built this one into an alternating tread stair in Všenory, Czech Republic. Found in Archiweb; more in TreeHugger, Czech Out Another Alternating Tread Bookcase Stair
Levitate Architects used a staircase to a loft-like bedroom to create an enormous amount of book storage space. Even though the staircase isn't very compact but could accomodate so many books that it would save some space anyway.
Pallet wardrobe is quite an inspiring project for your house corner. This wood pallet idea offer you with so many services at one time such as it can act as a staircase. Plus you would also be finding the service access of cabinets in it for placing some
Interior Old Skool Black Speaker Vintage Wine Bootle Brown Wooden Varnished Cabinet Black Stained Wire Mesh Stair Chocolate Wooden Varnished Wall Shelves Brown Varnished Parquet Floor Modern Under Stair Storage Solutions