Peek! A gun in a casemate, just waiting for some target to conveniently present itself. Guns in casemates never had much of what one might call a wide field of fire, instead depending on things floating slowly before them...and as far as I can tell, the casemated guns of America's starforts were hardly ever employed in their intended fashion. The wide-open terreplein, or a fort's upper gun deck, proved a much more practical location from which to utilize cannon.