I used two huge sheets of brown packing paper to tape on our own "cave" walls (a corner in the living room we covered with blankets). I had been saving that packing paper for months! It originally came in a package I'd ordered from Amazon and I knew it would come in handy!
We decorated our cave walls using crayons. Each of us got to do a different section. To find some real examples of cave drawings we could replicate, we took to the internet to find pictures of real examples of cave paintings. Here are the links to the ones we really liked:
This was such a fun project because it involved learning, a creative project, and imaginative play! Molly (6) loved finding real examples of cave drawings and discussing what each image stood for or what story it would tell. As for the actual drawing part? My kids ventured in their cave to keep adding to it all week! Finally, both of them had a blast pretending to be cave men.... or even explorers discovering the drawings we'd done and speculating about the cave men who lived there. Weeks later our cave drawings are still up!