Is New Orleans really so deep under the sea level or it is an optic illusion?

[Ulli]

In the Netherlands and in some parts of East Frisia it is like this, but our dams look like this:





and here are at least three dams in line. First comes the Summer-dam. It is built mainly for agricultural and gaining newland-reasons. So the sheep and cows are able to eat grass during the summer.

Then comes the Winter-dam. It is very high and strong and for the storm tides. In many cases the winter-dam is followed by the old dam of the previous coast-line.