<a href="https://en.wikipedia.org/wiki/16%22/50_caliber_Mark_2_gun" class="extiw" title='en:16"/50 caliber Mark 2 gun'>16-inch 50 caliber Mark 3 naval gun</a>, deployed as coast defense gun, at the United States Army Ordnance Museum (Aberdeen Proving Ground, MD).
Mark Pellegrini
CC BY-SA 2.5
<span class="int-own-work" lang="en">Own work</span>