From the Exploratorium's page:
"The Wave Organ is a wave-activated acoustic sculpture located on a jetty in the San Francisco Bay. The concept was developed by Peter Richards and was installed in collaboration with sculptor and master stone mason George Gonzales. Inspiration for the piece came from artist Bill Fontana’s recordings made of sounds emanating from a vent pipe of a floating concrete dock in Sydney, Australia."
It was constructed from pieces taken from a local cemetery.