Back in 2008，we went beach combing in Niigata (North West Japan). We found a bottle that had floated in from North Korea across the Sea of Japan (North Korea, China, Russia and South Korea are on the other side of the sea). We went back today to see if we can find something interesting. Nothing from North Korea this time, but enough stuff from China and South Korea.
The giant concrete tetrapods are breakers used to reduce the energy of the waves to prevent soil erosion.