From Hamburg we went north to the small harbor city of Husum, and then to the island of Amrum. Both are on the North Sea, a really unique landscape/habitat. The shoreline consists of sandy beaches and mudflats, very shallow areas that change drastically with the tides. The area also floods very easily, so the people have constructed a system of dikes which protect them from the sea.
Here I put two pictures together of the same set of stairs, at high and low tide. At high tide it was just deep enough for me to swim in(below) and at low tide you could walk out into the mudflats, a sticky kind of mud.
Below: the mudflats at low tide. In German called the Watt, this kind of habitat is called the Wattenmeer.
Amrum, different from Husum, has sandy beaches all around the island. Below is a picture I found on the web with an aerial view. The sandy beaches are expansive, unbelievably wide. At the widest it is 2.5 km. To the east of Amrum is the island Föhr, which is where we started our hike at low tide between the two islands. Behind the two you can see a third island, Sylt, the most famous of these islands (today you can drive and take a train to Sylt, which makes it much easier to access, we had to take a ferry to Amrum). I think the accessibility makes it more well-known, Amrum is definitely unbeatably gorgeous. :)
Below: North Sea at Amrum, Michael swimming at high tide.
Below: low tide during our hike between Föhr and Amrum, see post "Wattwanderung"