Egypt's cultural history is so rich that the whole world can recognize it.

You've probably learned about mummies, the pyramids, and other ancient artifacts from Egypt's long history at your local museum.

But a surprising find this week has baffled historians, and could teach us all something new about Egyptian history.

The Black Box

Archaeologists searching underneath an office building in Alexandria discovered a massive tomb with a number of surprising features.

The huge black box is almost definitely a sarcophagus, a traditional Egyptian coffin with a mummified person buried inside.

But while sarcophagi are a dime a dozen in Egypt, this one really stands out.

For one thing, the stone coffin is jet black and made of granite, which gives it a very creepy look.

It's also enormous, measuring 8 feet long and 5 feet wide, making it probably the largest in Alexandria's history.

Experts say that the tomb is still sealed with masonry, meaning it hasn't been opened since it was buried, maybe up to 2,000 years ago.

That also means the coffin's owner is likely still inside, along with the clothes and jewelry they were buried in.

Since most sarcophagi are found after they've been looted by grave robbers, that makes this one extremely valuable.

Whose Tomb Is It Anyway?

As of now, the tomb is being watched by armed guards as researchers continue to study it.

They will use CT scans and X-rays to peek inside the tomb and learn more.

The only hint to the owner's identity is a white alabaster bust buried with the coffin, but it's badly damaged.

From what they know so far, they guess that the tomb dates back to the Ptolemaic period, between 305 B.C. and 30 B.C.

Alexandria was given its name by Alexander the Great, whose adviser Ptolemy came to rule Egypt, followed by his descendants.

Ancient Alexandria was home to a number of impressive landmarks, including the massive Library of Alexandria and the Pharos lighthouse, one of the Seven Wonders of the Ancient World.

While this history is thousands of years old, archaeologists are learning more every day about Egypt's surprising past.

We can only guess who might be buried in this mysterious tomb, but it sure makes history a lot of fun!

Here are more articles about surprising history:

• The history of this Philadelphia asylum will keep you up at night.
• The FBI's most viewed case file might surprise you.
• Everyone knows Spam, but do you know its history?

[H/T: Smithsonian, Live Science]