This upcycled cardboard building set is a terrific open-ended toy that won't cost you a cent! All the materials come from the recycling bin.
Don't Throw Out Your Boxes! Creative Box Recycling Ideas for Children
100 Modern DIY Dollhouses Made From Recycled Supplies
DIY Upcycled Cardboard Building Set from the Recycling Bin
DIY Desk Organizer from Recycled Materials - Mod Podge Rocks
Make Recycle Bin From Cardboard
DIY Cardboard Box Toy House - Little Red Window
29 Creative Recycled Cardboard Crafts for Kids
30 BEST RECYCLED TOY CRAFTS FOR KIDS
What can you make with materials found around the house?
Cardboard recycling rates drop as shopping on , Walmart.com surges
Sustainable Cardboard House : 6 Steps - Instructables
25 Brilliant Ways to Upcycle Packaging Materials
48 Easy Creative Recycled Art Projects for Kids • B-Inspired Mama