Every first Monday of the month, they test the Air Raid Sirens in Holland. I know there is nothing wrong. They start at midday and it lasts 2 minutes. But it is a very unsettling feeling. The whooping sound is a really unpleasant one. Creates an immideate feeling of doom. Like back in the 50s and 60s. And then again in the 80s. When we were all expecting The Bomb to drop any minute now.