Special scanners have been able to show researchers that the stone structure is not as dense in a certain area of the pyramid.
They believe that the empty space the scanners have located is big enough to fit a 200-seat passenger plane inside!
Now the plan is to find out what is inside this space – if there is anything in there at all?
What is the Great Pyramid?
Khufu’s Pyramid, also known as the Great Pyramid, is the largest of the three Pyramids of Giza. It stands at 140 metres tall, that’s over 23 giraffes stacked on top of one another!
It was built more than 4000 years ago for the Pharaoh Khufu.
Pharaohs were expected to become gods in the afterlife. These pyramids were filled with lots of things that people thought would help pharaohs in the next world.
When the pyramids were first built, they were covered in bright, white limestone and full of lots of different treasures. Sadly, many of these treasures have been stolen.
What’s inside the space?
Scientists had a very special technique to find this space in the pyramid.
They used something called muography. This is where they record the speed at which high-energy particles travel through or are reflected by hard surfaces, like rock.
Now the question that the researchers need to answer is what is inside that space?
One French scientist, Jean-Baptiste Mouret, has suggested that they might drill a very small hole in the side of the pyramid that leads into the space.
They would then send a tiny robot down the hole to look inside!
There is lots of excitement about what might be inside this space and there are different theories as to what it could be.
However, some scientists have said that it could just be an empty area purposely designed by the builders of the pyramids.
This might have been done to take some of the weight of the stone off the Grand Gallery which is directly below it.
So it looks as if the mystery of what’s inside this ancient pyramid won’t be solved anytime soon.