1st Monday of the month madness
So when I first moved over to amsterdam as a youth I was rather partial to the odd three day bender at the weekends, this involved little sleep and usually left me in a state of almost euphoric paranoia. Long story short, I was wandering home through a compleltely empty part of town on a monday morning and hear this godawful wail start up "oooooooooooWAAAAHHHHHHHHHH" and then another and another nearer and nearer to the point I could hear nothing else. Panic took me, where was EVERYONE and why were all these air raid sirens going off, who the fuck was attacking and how do I get to the coast, quick get to a canal and steal a boat, a fast boat, yes that'll do it, you can get home to ireland if you're lucky. And then it stopped. And an old man with a dog walked around the corner and it shat by lamppost and they went past me as if nothing had happened.

I later found out that every first monday of the month they test the flood warning sirens. They still freak me out a bit every time i hear them.

EDIT- found a clip of the insanity, here www.youtube.com/watch?v=rEsm1VDA1UA&feature=plcp
(skunkito, Sun 17 Jun 2012, 15:43, closed)

I also jumped the puddle
From the land of green to the land of orange and they freaked me out first time too.

They also use them for other things, like when that fireworks factory went on fire.
(posthumous mince is tiptoeing through the tulips, Sun 17 Jun 2012, 21:03, closed)