Here is a storage for all the serious and non-serious stuff in a classroom. The bins made in plywood are removable with handles, that can be removed and taken to an activity circle. They may contain toys/ clay/ pencils/ blocks etc. etc. They can be used from front and from the top.
One level high storage is at seating for kids in age group of 3-6 yrs.
One could keep adding as the need arises. The sides that are covered in board has handles to indicate the point for lifting.
And now coming to even better feature is that the design allows for shelves as much as for bins. So go ahead.. store books, toys, junk and take it where you want.