Sometimes, our daily Geo Quiz involves a long answer. This one's short, just two letters long.
Some names consist of just one letter. For example there's a river in northern Russia named Y, just Y. Another river in the Scottish Highlands is called E. Oh, and supposedly there's a place in Panama called U.
But for our quiz, limit yourself to two letters.
Name an ancient Mesopotamian city located in what is now Iraq. Its cultural hey days were more than 4,000 years ago, but its ruins survive to this day.
"There's the famous royal cemetary, there's the ziggurat, there are public buildings of all kinds, you can really get a sense of what a Mesopotamian city looked like," says anthropologist Elizabeth Stone.
Some of this city's ancient treasures of gold and lapis lazuli are exhibited in Iraq's national museum in Baghdad. Others are in the University of Pennsylvania's Museum of Archaeology and Anthropology.
Can you name the ancient capital of Mesopotamia?
This week, passover dinners, or seders, are happening in many Jewish households. Some recount the biblical narrative of Moses and the ten plagues. Others take the history further back, to when Abraham left Mesopotamia. His home is said by some to be the city of Ur in what is now modern Iraq.
And Ur, by the way, is the answer to our Geo Quiz.
So what's there today? What remains of its ancient glory of the capital of Mesopotamia? Is it important to preserve and protect the archaeological ruins of Ur?
We put the questions to Elizabeth Stone, an anthropologist at Stony Brook University who's been to Ur in Iraq.