The answer to today's Geo Quiz is: Timbuktu, Mali.

The city was once a wealthy metropolis and key outpost for trans-Saharan traders.

To hear more about the history of this African city, Listen to our interview with Marq de Villiers, author of Timbuktu: The Sahara's Fabled City of Gold

From the publisher:

"Timbuktu-- the name still evokes an exotic, faraway place even though its glory days are long gone. Unspooling its history and legends, resolving myth with reality, Marq de Villiers and Sheila Hirtle have captured the splendor and decay of one of mankind's treasures.

Founded in the early 1100s by Tuareg nomads who called their camp "Tin Buktu," it became, within two centuries, a wealthy metropolis and a nexus of the trans-Saharan trade. Salt from the deep Sahara, gold from Ghana, and money from slave markets made it rich. In part because of its wealth, Timbuktu also became a center of Islamic learning and religion, boasting impressive schools and libraries that attracted scholars from Alexandria, Baghdad, Mecca, and Marrakech. The arts flourished, and Timbuktu gained near-mythic stature around the world, capturing the imagination of outsiders and ultimately attracting the attention of hostile sovereigns who sacked the city three times and plundered it half a dozen more. The ancient city was invaded by a Moroccan army in 1600, which began its long decline; since then it has been seized by Tuareg nomads and a variety of jihadists, in addition to enduring a terrible earthquake, several epidemics, and numerous famines. Perhaps no other city in the world has been as golden-- and as deeply tarnished-- as Timbuktu.

Using sources dating deep into Timbuktu's fabled past, alongside interviews with Tuareg nomads and city residents and officials today, de Villiers and Hirtle have produced a spectacular portrait that brings the city back to life."