The Great Barrier Reef (Photo: Nathan Hughes Hamilton/CC BY 2.0)

As it turns out, the Great Barrier Reef, might not be the only great thing sitting in that portion of the ocean. According to Smithsonian and other outlets, a newly-mapped reef also lies in the waters near the famous Great Barrier Reef. But it isn’t made of coral.

The existence of this reef has been known about for decades, but, up until recently, its exact scope and scale has never been truly known. But with the use of new laser mapping technology, the natural formations have become much more clear, and appear to be much grander than previously imagined.

What’s been hiding beneath the Great Barrier Reef? A deeper, massive reef. https://t.co/4MV6FQtZgq — Smithsonian Magazine (@SmithsonianMag) August 30, 2016

Just beyond the Great Barrier Reef, it turns out, there are huge swaths of doughnut-shaped mounds known as bioherms, that cover over 2,000 miles of deep-sea real estate. The mounds are formed from algae which become flakes of limestone when they die, piling up on each other and creating new geologic structures. These structures easily overshadow the nearby coral reefs in terms of size, and are three times larger than researchers even estimated.

While the scale of the newfound reef is impressive in its own right, scientists are also hoping that by studying the bioherms they can gain more insight into the ecosystem surrounding the endangered Great Barrier Reef.