These Dutch feats of engineering were finished in 1932.
The outer dam is called Houtribdijk Dam that separates the Inner Markermeer from the outer Ijsselmeer. (A7).The outer dam is called Afsluit Dijk and goes south from Lelystad back to Amsterdam.
Did you know that the thermometer was invented in Amsterdam in 1714?
Our house in Amsterdam had an interesting, stylish hydrometer. It bore the name of its maker, Jan van Agteren. He lives in Lelystad, at the tip of the second dam on our way back to Amsterdam. So our round trip would come full circle.