World War II Bunker on the River Berounka, Nymburk(?), Bohemia (CZ), 2014

I took this on a bike trip from Beroun to Smichov, which would be my longest bike trip to date. I've called structure this a "bunker," but it's technically a pillbox, if I'm not mistaken, both because of its shape, and because it's above ground. I don't know whether it was built by Czech forces during the 1930's, or by Nazi Germany, but it's unlikely to have been armed with more than a heavy machine gun. It would have been built to stop enemy traffic on or alongside the River Berounka, visible on the right.