The archaic term "air protection" represents a particular era: a way of thinking, a political-administrative concept and a set of technical-organizational measures to protect the civilian population of cities from air attacks. The air protection policy that the Netherlands reluctantly established in 1933, following the example of Germany and England, has now been examined for the first time. Central to this are the civilian shelter and that for the occupying power, the bunker. During World War II, Reich Commissioner Seyss-Inquart had a complete Shelter City built: the Clingendael estate near The Hague. Shelter City offers both an architectural-historical approach to the Shelter City and an overview of its structure, such as disaster planning, food storage and citizen education. Moreover, from a historical perspective, Koos Bosma casts a critical eye on current policy. Our government actively involves its citizens in the dangers of terrorist attacks. Isn't this now outdated? And how do we deal with the legacy of the Shelter City?