Researchers in Brazil say they've found an "undiscovered wonder of the world." But after learning about it, we kind of wish they could undiscover it again.
What they found in the forests of northeastern Brazil are more than 200 million mounds of dirt, some over 4,000 years old.
And underneath those mounds, researchers say termites have built an enormous network of tunnels larger than Great Britain.
While the mounds were spotted by researchers in 2004, locals have always known about them. But a new study of these incredible structures published in Current Biology on Monday was full of unbelievable details.
"What's strange is they're really regularly spaced," lead researcher Stephen Martin told CBC Radio.
Each of the mounds is around 10 feet high, 20 feet wide, and spread out 30 to 40 feet from the next one. Taken together, the wide expanse of termite hills can actually be seen from space.
In fact, Martin and his team guess the amount of soil excavated by the bugs, 2.4 cubic miles of dirt, is enough to build the pyramids of Giza 4,000 times.
"As humans, we have never built a city that big, anywhere," Martin told The New York Times.
While tunnels underneath the mounds are dense, Martin says each hill only has one vertical tunnel, which the termites use to climb up to the surface.
They're actually more like waste hills, where the termites can dump the dirt they remove while building tunnels and rooms underground.
But the bugs will also crawl up during the rainy season in search of leaves, which they stockpile in large "galleries" under the dirt.
The study says that the bugs were allowed to build their massive homes undisturbed for centuries because the soil in the region is poor, so humans have avoided growing crops there for thousands of years.
The results of their work are now the oldest living structures, "made by insects and still occupied today," as Martin said.
While the rest of us are stunned to learn about this impressive termite burrow, Martin is still digging into it to learn more about the incredible structure.
One mystery he has yet to solve is where the termite queens live, because none of the excavated tunnels have featured a chamber for these special bugs.