Like a building block toy, this modular bookcase allows you to create shelves with limitless shapes and dimensions. The system is composed of three joints and four panels in plastic with modular dimensions of the same depth. Assembly involves simply pressing the elements to lock them together, without the help of tools or the use of screws or metal pins. The special solidarity of the structure allows the system to be used as a self-supporting dividing barrier or even as a shelf-tower in the middle of a room.