Mike Gerrells from Harvest Church in Billings, MT brings us these walls of rubble.
To create this design Mike used 2″ and 3″ foam blocks in 2′ x 4′ sections. He traced out the rock formations with a sharpie and used a hot knife to shape the rocks into a rock wall. Mike used spray paint to melt and rough up the edges. Then he used water based paint and used three different colors of brown paint to color the foam boards.
The center graphic was a printed banner which he attached to a flat wall then wrapped the foam blocks around it. The keys and drums got a similar treatment with foam rock boards held together with grill skewers. The whole set cost less than $400.