Holland - stenen Beer Sint Aagtendijk / Stone wall St. Aagtendijk
Opposite of Fort Sint Aagtendijk, which is also part of the:
Stelling van Amsterdam or Amsterdam Defense Line, you will find remnants of a small stone wall and the abovesign.
The English translation is:
Stone wall Sint Aagtendijk
Stone wall controlls water.
This small wall covered with natural stone once formed an important part of the Amsterdam Defense Line. Because the area here is pretty high (and difficult to flood) a canal was especially dug to this purpose (side channel A). This channel got its water from the Northseachannel.
The wall was in the past 20 meters long and separated the waterinlet at the left of the channel. Where the wall does not exist any longer now an earthen dam is put in its place.
The city of Amsterdam (Holland's capital) is surrounded by a chain of forts, dams and sleuzes with a length of 135 kilometer. They were built in a very short period (in between 1880 and 1914) after the French-German war of 1870-1871. Their purpose was to protect Amsterdam. The principal idea was to flood the land surrounding Amsterdam. In a military sense the chain of fortifications, dams and sleuzes was 100 % effective, it was impossible to break through this defense line, until ... the arrival of aeroplanes. By this the whole system became completely and totally obsolete. Since it is a unique defense system in this part of the world it was put on the Unesco World Heritage List in 1996.
If you want more info:
http://www.stelling-amsterdam.org/english/index.htm
The info on this site is in Dutch and in English
De info op deze site is in het nederlands en in het engels.