Curonian Spit. A narrow strip of land 98 km long and 400 m wide at its narrowest point to 4 km wide at its widest. This is the largest sandy mound in the world, and the second highest dunes in the world (higher only in the Gulf of Gascony in France), their age is more than 6 thousand years. I happened to be there more than once, due to the fact that my brother lives very close, in the resort town of Zelenogradsk (formerly Kranz, East Prussia). This is how fate happened that we both live in cities that not so long ago were Russian and Russian, my city was Finnish, and his was Prussian.→