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Normaal Amsterdams Peil (NAP) - Dutch NAP Level Markers
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Managed By: Icon Here Dutch NAP Markers
Description:
The Dutch NAP network consists of approximately 35,000 visible sounding marks, usually bronze bolts with the inscription NAP, installed in quays, walls, buildings or on poles and also 400 underground sounding marks. The differences in height between the survey marks are accurately recorded.
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