You know that gigantic LEGO Indiana Jones boulder? Turns out that only the outside is LEGO. The inside (based on this photo) is made of styrofoam. We suppose that it would be way too cost-prohibitive to build the entire boulder out of LEGO, but that doesn't make us any less disappointed. [Photo Credit - Thanks Mike!]
I wonder what the weight difference would have been between solid Lego and Styrofoam core versions. Probably ridiculously heavy for the Lego version. Would have easily crushed Lego's on the bottom of the "bolder", and obliterated the rear-end of the van it ran into.