Sea organ

http://en.wikipedia.org/wiki/Sea_organ
https://www.youtube.com/results?search_query=Sea+organ

three times size of Earths oceans

http://timesofindia.indiatimes.com/home/science/Massive-underground-reservoir-of-water-three-times-the-size-of-Earths-oceans-located/articleshow/36493512.cms

Perspective