https://www.youtube.com/watch?v=u6XripCQB2w I found this when I was on trip. It's near Balaton. Does anyone know what are these sirens? Please help. Here's the location: https://www.google.hu/maps/@47.0605743,18.0259199,3a,75y,326.35h,108.92t/data=!3m6!1e1!3m4!1szuO59ostBuEq1ujzUbLEyQ!2e0!7i13312!8i...