A submarine pen (U-Boot-Bunker in German) is a bunker which is designed to protect submarines from air attack. The term is generally applied to submarine bases constructed during World War II, particularly in Germany and the occupied countries which were also known as U-boat pens (after the phrase "U-boat" to refer to German submarines).
Famous quotes containing the word pen:
“Words are but air; the pen leaves a mark.”
—Chinese proverb.