Recently the dyke benchmark (the “Huddestone”) was restored. During the demolition of “De Nieuwe Brugsluis” it had been lost, but it was rediscovered during the construction of the metro. The image below show this historical stone both before its loss and after its rediscovery.
During the night of Thursday 6th december 2013 the sea level rose to 3,99 meters (about 13,09 feet) above NAP. That was the highest level that had been measured there since the 1953 disaster, when the water reached a level of 4,55 meters (14,93 feet) above NAP, the dykes breached in many places and more than 1800 people drowned.
Minister of Transport, Public Works and Water management Neelie Smit-Kroes opens the NAP monument on 18th May 1988
On 18th May 2013 it was 25 years since the NAP monument was opened by the Minister of Transport, Public Works and Water management, Mrs Smit Kroes.
The NAP-project was designed and implemented by Louis van Gasteren and Kees van der Veer. The project was realized by the NAP-foundation on the occasion of the opening of the new Amsterdam City Hall (De Stopera). After its renovation, expansion and the provision of an exhibition the NAP-monument was re-opened on the 12th Oktober 2010 by Crown Prince Willem-Alexander.