What actually lies underneath the massive ice sheet of the Antarctic still remains a mystery.

But recently, scientists surveying the region discovered that it might be hiding the world's biggest canyon, Sputnik News reported.

Through satellite data, researchers from the Durham University noted that a canyon that's more than 1,000 kilometers long with levels of up to a kilometer deep may be hiding underneath Antarctic's ice. This dwarfs the Grand Canyon in Colorado which is 446 kilometers long.

Aside from the canyon, the researchers also think that the ice sheet is also hiding a 1,250 square kilometer subglacial lake. Both the canyon and the lake are believed to be underneath the Princess Elizabeth Land region of Antarctic.

It is not yet clear exactly when and how this impressive landscape was formed but the researchers believe it existed long before the ice sheet of the Antarctic developed. Another theory suggests that the canyon was created by the water flowing underneath the region's icy surface.

"Our analysis provides the first evidence that a huge canyon and a possible lake are present beneath the ice in Princess Elizabeth Land," lead researcher Dr. Stewart Jamieson said in a press release.

"It's astonishing to think that such large features could have avoided detection for so long," he added.

According to the researchers, they were able to gather information on the land beneath the ice by mapping its surface. Through the overall shape of the ice sheet's surface, they were able to get an idea of its underground topography.

They, they used radio-echo sounding technology to come up with direct measurements of the natural landscapes hiding underneath the ice.

For Jamieson's team, the new findings on the underground world of the Antarctic are significant discoveries since little is still known about this region. The head researcher even noted that people know more about the features of Mars than the subsurface of the Antarctic.

"This is a region of the Earth that is bigger than the U.K. and yet we still know little about what lies beneath the ice," he said. "In fact, the bed of the Antarctic is less well known than the surface of Mars."

"If we can gain better knowledge of the buried landscape, we will be better equip to understand how the ice sheet responds to changes in climate," Jamieson added.

The study drafted by the researchers was published on December 22, 2015, in the journal Geology.