Sonic wonders of the world: Gong Rocks at Moru Kopjes in the southern Serengeti National Park,Tanzania

"We're used to going on our travels and looking out for beautiful vistas and wonderful architecture, but we tend not to think about the sound," Trevor Cox, (a British acoustic engineer who, armed with a microphone and digital recorder, has spent several years earwigging his way around the planet in search of what he calls its "sonic wonders."), who was struck by the notion of exploring a wider world of sound while investigating echoes in, of all places, a London sewer.

"So then I began to think about where I would go if you wanted listen to the most remarkable sounds in the world and I was surprised to find there was relatively little information," he tells CNN. "That's when I thought I should gather it myself."

Where: Moru Kopjes, Serengeti National Nark, Tanzania -- and other sites across Africa

What: Not a prog rock group, but one of several eons-old boulders that produce mellow notes when whacked with smaller stones.

Tonally, their range can be a bit on the monotonous side, but the fact that it probably resonates back to the dawn of civilization helps raise neck hairs.

Cox says: "Among the earliest evidence we have of what our ancestors might have listened to is left over bits of musical instruments like these rock gongs."

Stay: You'll need pockets big enough to hold a gong rock to afford to stay in the swanky safari camps of the southern serengeti. 

A tourist playing the 'gong' rock (sounds like a bell)

Click the link below to see the video and hear the sound of this mysterious rock!
Hear the rocks

The gong rock in the plains of the Serengeti National Park, Tanzania is located on one of Serengeti's Kopjes. It is the oldest instrument yet discovered and its many dents tell us a story of how early man invented music playing simple melodies on the metallic sounding rock.The pitted surface of the Gong Rock is testament to its use by the Maasai tribe to send sound messages across the vast distance of the African savannah since ancient times.