This map is still in the very early stages, and may take years to complete. Feel free to add siren locations anytime you want. There is a color key for different manufacturers. Mystery sirens are represented by a light-gray rhombus. Multiple adjacent sirens are represented by a white star. Removed sirens are represented by a circle, not a pin.
https://mapsengine.google.com/map/edit? ... GSyyrT1PpA