Free Wooden Playset Blueprints Where Would I Find Produce And Wine Wooden Crates For Free?

Where would I find produce and wine wooden crates for free? - free wooden playset blueprints

The need for shelving / storage idea, but I have no idea what kind of places, but still used wooden crates. It is the idea of going to the store for cardboard boxes, if they want out of the wood. Ideas? Thanks