Vienna

There are two of these odd concrete structures in this park and we stood slack jawed trying to figure out what they were.

Each is constructed from crudely cast concrete and is about 8 or 9 stories high.  Up close they are distinctly weathered and look very unwelcoming.

These are flak towers built by Hitler after he realized how much damage allied bombs could do.  The towers were equipped with anti-aircraft guns.

It would cost too much to take them down so there they stand.