Sometimes pretty comes with a price:

The U.S. Army is investigating incidents of unexploded World War I-era munitions showing up in clamshells used as paving material for driveways and parking areas in Delaware, Maryland and Virginia.

The ordnance was dredged up during the past 18 months from the ocean floor during mechanical clam harvesting operations off the New Jersey coast, in the vicinity of Atlantic City, according to Robert Williams of the U.S. Army Corps of Engineers, which is conducting the investigation.
...
Some grenades were found inside the clams.

And just how big are these clams? Boy, that'd be a nasty surprise for some seafood cook, eh?

Ron gets a rusty but potentially explosive no-prize for bringing us this "your driveway, it asploded" story.