How to utilize the space under the stairs

I so like nooks and crannies. In our current home there appears to be no space under the staircase since it is covered by a wall. But if you do have space under your staircase here are some creative ideas to utilize that space. Here is a book shelf with seating area.

A cozy spot to curl up in and read a book.

A whole room under the stairs.

Shelves to display your collections.