Hesitant to dig up a month-old thread...but I found a siren that possibly qualifies for this challenge.
For the longest time, I thought that large round feature on top of the water tower in Center Point, Iowa was an air vent of some type...
Nope, it's a Federal SD-10! Yes, it's mounted all the way to the top of the water tower, easily 150 feet up or more.
It looks so small mounted waaaaaay up there. This is about as close as I could get before the siren disappears behind the curvature of the water tank.