Scientists discovered a forgotten 'yellow brick road' at the bottom of the ocean

The ocean floor has always been the biggest mystery on Earth. However, in 2022, scientists saw something so strange that they had to stop and look. It was a carefully paved “road” about a kilometer below the surface, under the Pacific Ocean, that looked as if it had come from a fantasy movie. The best part? Everybody could see it happen live.

Wait, a road?
The exploration vessel Nautilus was on a routine survey of the Liliʻuokalani Ridge, a chain of deep-sea mountains just north of Hawaii in the Papahānaumokuākea Marine National Monument (PMNM). It is one of the world's largest marine conservation areas, bigger than all the US's national parks combined. But only a mere three percent of its seafloor has been visually explored.

The cameras of the remotely operated vehicle panned across the summit of Nootka Seamount, some three thousand feet below the surface, and produced what looked, for all the world, like a yellow brick road. The response from the research team said it all. “It’s the road to Atlantis,” one researcher said on the radio. “Yellow brick road?” said another. A third simply added, “This is bizarre.”

So what is it, really?
This is not Oz. It’s geology, pulling off a scary good impression of city planning.

The Ocean Exploration Trust said the formation is a fractured flow of hyaloclastite rock, volcanic material formed when broken rock falls to the seabed during high-energy eruptions. The 90-degree fractures you see in the footage are probably caused by the stress of heating and cooling from multiple eruptions at what geologists call a baked margin. In short, lava met water, broke itself up, cooled and shattered into something that looks very much like brickwork. No ancient engineers required.

The radio crew said it was like a “baked crust” that you could just peel right off, which honestly makes it even weirder. The seamount is a Cretaceous-age feature, between 66 million and 145 million years old, and the 2022 dive marked its first visual survey.

The ocean is far less explored than you might think
This is the part where things are put into perspective. In a 2025 landmark study published in Science Advances, researchers at the Ocean Discovery League found that, even though the deep ocean covers 66 percent of the planet's surface, humans have seen less than 0.001 percent of the deep seafloor in 67 years of recorded deep-sea dives. The search area is about 3,823 square kilometers, slightly larger than the state of Rhode Island, the smallest state in the United States.

Read it again. The entire area of the deep sea explored visually by humans could fit inside Rhode Island.

“More than 99.999 percent of the deep seafloor has never been seen,” said Dr. Katy Croff Bell, president of the Ocean Discovery League and lead author of the research.

Why this matters to all of us
The deep ocean is more than just a dark, empty void. It supports many ecosystems and provides vital services such as oxygen production, climate regulation and key drug discoveries. What happens down there impacts life on land, including in the US, where fisheries, coastal communities and climate patterns are all connected to the health of the ocean.

The lack of exploration of this vast region is a critical problem for science and policy, as threats such as climate change and potential deep-sea mining speed up, says the Ocean Discovery League.

The yellow brick road moment wasn’t just a fun shareable clip; it was a reminder of how much we don’t know about the planet we live on. Each descent into those depths is, in effect, the first time that human eyes have ever seen that part of the Earth. And if a stretch of ancient volcanic rock can fool scientists into thinking they've found the road to Atlantis, just imagine what else is waiting down there.