I'm here in Egypt, standing on the Giza Plateau, which is known for its massive pyramids.
The pyramid closest to me is the Pyramid of Khafre, named for the pharaoh who built it.
The farther one is called the Great Pyramid of Giza.
The Pharaoh Khufu—Khafre's father—built that one.
You might find this hard to believe, but these pyramids were built over four thousand years ago.
Hidden in the gray dawn, there's something else.
Do you see it? It's the back of a massive head!
You're looking at the Great Sphinx of Giza!
You've probably already heard of the Great Sphinx of Giza.
It's the tallest stone statue ever built in ancient Egypt.
Scientists believe it was created around 2500 BC, maybe during Pharaoh Khafre's reign.
Carved from limestone, the statue has a lion's body and a person's head.
The Great Sphinx really is "great"; its massive body is about 73 meters long and 20 meters high.
Its head is bigger than a mansion, and its body weighs about the same as fifty jumbo jets!
The sphinx, a mythological creature, first appeared in ancient Egyptian and Greek culture.
In art and stories, the sphinx always has a lion's body and a human's face.
But while the ancient Greeks portrayed the sphinx as female, usually with wings, the ancient Egyptians portrayed the sphinx as male.
Many Egyptian temples and pyramids have sphinx statues standing guard; the ancient Egyptians probably saw them as benevolent protectors.
The appearance of the sphinx in culture has given scientists clues about the Great Sphinx monument.
But many mysteries still surround it. For instance, scholars wonder about the Sphinx's face.
Was it carved to look like a real person?
Perhaps Pharaoh Khafre or his father, Pharaoh Khufu?
Many experts suspect the Sphinx has Khafre's face.
That's because Khafre had a beard, and so did the statue, originally.
Why was the statue built? Maybe it was constructed to honor the pharaoh—a symbol of his awesome power.
Or perhaps it was put there, facing east, to worship the sun.
In ancient Egypt, the horizon was believed to be where the dead entered the afterlife.
The Great Sphinx could be guarding that sacred spot.
And who built the Great Sphinx? While the nearby pyramids have inscriptions and clues about their builders, the Great Sphinx reveals almost no clues.
Scientists think it was created by the same team that constructed one of the pyramids.
But since these pyramids were built at different times, it's hard to know for sure which team that was.
And here's another mystery about the Sphinx's construction—it was never finished.
Scholars don't know why, but the builders seem to have abandoned the project shortly before its completion.
I was surprised to learn this, but sand has buried the Great Sphinx on and off throughout most of its existence.
According to a story from around 1400 BC, a prince was hunting in the hot desert and saw the Sphinx's head sticking out of the sand.
He decided to sit in the shade under the head.
The prince fell asleep, and when the sun reached its highest point, the statue appeared to the prince in a dream.
It said that if the prince uncovered the rest of the statue, the prince would become the next pharaoh.
The prince did as the statue said, and he became King Thutmose IV!
Oh, and over time the Great Sphinx was buried under sand again, of course!
Being buried under the sand may have helped to protect the Sphinx.
If the Sphinx had not been buried for most of its existence, it would have disappeared long ago.
Still, the statue has suffered a lot of damage over time.
Its nose is missing—gone forever, probably chiseled out by looters.
But that's not the worst problem. The statue is slowly turning to dust!
Limestone is soft, and wind, water, and sand have weakened the statue over time.
Two more recent threats to the Great Sphinx are pollution and rising groundwater.
Today the stone is treated with special chemicals that help protect it from the pollution.
And holes have been drilled in several spots near the statue to prevent water damage.
Luckily, scientists also used sophisticated laser scanning equipment to closely examine the statue.
The equipment helped to identify its weak spots, and now scientists can take steps to limit future damage.
Thousands of years ago, as the Great Sphinx sat here, gazing at the rising sun, it was probably guarding the pharaohs' entryway to the afterlife.
Now it's our time to be the guards.
We have to watch the ancient Sphinx carefully and take good care of it.
That way, thousands of years from now, people will still be admiring its beauty.