A large chunk of an exploded Rodman Gun. If you've never tried to lift one, I can tell you that cannon of any size are quite impossibly heavy: The smallest Rodman Gun, a ten-incher, tipped the scales at over 15,000 pounds. When these guns were no longer needed, it was far easier to block their bores, detonate them in place and pick up the pieces than it would have been to lift them whole and somehow manhandle them elsewhere.

That, however, is not how this particular bit of iron was detached from its gun: According to nearby signage, the Rodman Gun in question exploded in the presence of Robert E. Lee. "I most humbly thank you for this exciting display," said Lee, "...but in future I believe I would prefer a less destructive tribute."*

*He probably didn't really say that.