Ice cave in the Skaftafell National Park in Iceland. Ice caves collapse and new ones form as each glacier grinds slowly towards the sea. Local guides can help you (without dying) find one. (Visit Skaftafell National Park in Iceland.
The musical Sea Organ (morske orgulje) is located on the shores of Zadar, Croatia, and is the world's first musical pipe organs that is played by the sea. Simple and elegant steps, carved in white stone, were built on the quayside.