Stairs in an ancient dungeon.
donjon definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the heavily fortified inner tower or keep of a castle
Origin: old spelling, spelled of dungeon
donjon definition by American Heritage Dictionary
The fortified main tower of a castle; a keep.
Origin: Variant of dungeon.