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| Image: The caves were built long ago and rebuilt, modified and widened several times. Brickstone walls closed parts that wer not used any more. |
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| Image: The walls of the caves show remains of the digging work. And they show the typical layers of flint stones which formed along chemical borders in the ground water. |
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| Image: An air vent which was necessay only for the air raid, as this was the only usage in history with many people staying some time inside the cave. |
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