On Thursday, as a National Geographic expedition was exploring the waters around the Solomon Islands, its members spotted something that looked like a shipwreck underwater. Intrigued, they sent a diver down to investigate.

The world's biggest coral — an organism made up of about a billion polyps — is about three times bigger than the previous record-holder and was discovered by chance during an expedition off the Solomon Islands.

Researchers have discovered the world's largest coral colony in the southwest Pacific Ocean, in the waters of the Solomon Islands. Measuring an astonishing 34 meters wide and 32 meters long, the coral is a species called *Pavona clavus* and is believed to be over 300 years old.