 Safe rooms on civilian ships, sometimes called "citadels", are increasingly being installed as a countermeasure against piracy.When attacked, the crew can retreat into the safe room and call for help (which in the case of ships of some countries may include the intervention of military forces).Because of the nature of ship construction, the safe room is typically constructed in a concealed location within a void within the ship, to resist efforts by the pirates to find the crew before help arrives.