Researchers have been scoping out a unique range of hills and peaks on Mars, and now believe the area could contain a massive deposit of frozen water.

Dubbed Phlegra Montes, the area falls around the Elysium volcanic region of the Red Planet. The European Space Agency reports that the formation is a product of ancient tectonic forces, and is estimated to be 3.65–3.91 billion years old.

So, why do we now think there might be a ton of ice still there, buried approximately 65 feet below the surface? Because researchers are putting together new radar data from NASA’s Mars Reconnaissance Orbiter with info from other orbiter missions mapping the region’s geology, and they now believe “extensive glaciers” covered the region hundreds of millions of years ago — and it’s likely that water is still there.

Researchers say the strange tilt of Mars’ polar axis has caused some wildly significant climate changes over the years, which is why there could be buried glacier ice in what is now a mid-latitude of Mars.

If there is water buried under those hills, it could have far (far, far) reaching implications for future human settlers. Sure, there’s also water in other areas of the planet (namely the polar ice caps), but if we eventually plan to set up permanent settlements, we’re probably going to need to mine some water. Put an “X” on the map right here and start planning.

Just for fun, check out an artist’s rendering of how Mars may have looked millions of years ago with surface water below:

(Via European Space Agency)