Oder–Neisse line

The Oder-Neisse line is a border between two countries, Poland and Germany. It is the official border that divides the two countries. It was agreed on in 1945 after World War II, so Germany and Poland knew exactly where the line should be and how much space each country got to live in. The line follows two rivers, the Oder and the Neisse, That's why it's called the Oder-Neisse line.