Airraid shelters inside.
Each tower has two entrances on a different level, "Geschoss".
The stairs were made of wood.
They were connected to the public watersupply.
And to the public sewer system.
They had an extensive airfilter system.
A second Winkelturm houses a museum.
The airfilters were placed at the top floor.
One of the toilets.
An impressive display with airfilters.