If the sound of waves lapping gently onto the shore puts you in a trance, then it's time you listen to the Morske Orgulje -- or, the Sea Organ.
The crooning structure in the video above is a 230-foot long instrument on the coast of Zadar, Croatia, that plays mesmerizing harmonies using the movements of the sea.
The Sea Organ was conceived in 2005 by architect Nikola Bašić, after a new jetty was built to welcome cruise ships and their tourists to the charming port town.
On its surface, the organ looks like large marble steps leading into the Adriatic Sea. Below, however, lies a series of narrow channels that connect to 35 organ pipes. Each set of steps holds five organ pipes each and is tuned to a different musical chord.
As waves and wind push air through the channels, a song pours through the organ pipes and out onto the steps above. The sounds produced rely completely on the wave energy's random time and space distribution.
In 2006, the Sea Organ won the European Prize for Urban Public Space because it was a "perfect grandstand for watching the sunset over the sea and the outline of the [neighboring] island of Ugljan, while listening to the musical compositions played by the sea itself."
Below, listen to the organ wail its harmony on an especially rough day by the sea.