One Mountain, Three Seas
On Trójmorski Wierch in Poland, rain can flow toward the Baltic Sea, the North Sea, or the Black Sea.
9/20/2026In Poland, there is a mountain where a raindrop’s journey can depend on which side of the ridge it falls. Trójmorski Wierch, in the Śnieżnik Massif, is 1,145 meters high and sits where three major European drainage basins meet.
Water from one slope reaches the Baltic Sea through the Nysa Kłodzka and the Oder. From another slope, it travels through Czech rivers and the Elbe to the North Sea. From the third, it can travel through the Morava and the Danube all the way to the Black Sea.
This does not mean that the sources of three great rivers are on the summit. Instead, an unusual watershed there divides rainfall among three river systems. Trójmorski Wierch is one of only a few places like this in Europe. Most of Poland belongs to the Baltic Sea drainage basin; areas draining toward the North Sea and Black Sea together cover only about 0.3 percent of the country.