The Sea Organ (morske orgulie) is located on the shores of Zadar, Croatia. It is seventy meters long with thirty-five organ pipes built under the concrete. It is the world’s first pipe organ played by the sea. The movement of the sea actually pushes air through and the air holes along the top row of steps let the Sea Organ breathe in air to be transformed into musical sounds as the next wave plays its song. The waves will create random harmonic sounds.

[via Neatorama]