The Silk Road was an ancient, famous network of roads and trading posts that linked Asia and the Mediterranean region.

The modern nation of Afghanistan was a major thoroughfare of the Silk Road. Today, the region continues to be a crossroads for concepts of ancient and modern, East and West, geography and history.

Afghanistan is a land of rugged mountains. Still, this intimidating landscape actually helped ancient traders, says Dr. Fredrik Hiebert, a National Geographic Society archaeology expert.

"Those mountains and those rivers are the best things" to help along trade, he says. "Because what happened is you look at the mountains, and you see these valleys that go up into the mountains. Those are superhighways. You go up from the deserts, and you can go up through the mountains. You don't really have to know too much about navigation."

Graveyard Of Empires

Afghanistan sat at a key connection point between the empires of Asia, eastern Africa and southern Europe. Traders and travelers on the Silk Road could interact with the cultures of China, India, Persia, Arabia, eastern and north Africa and the eastern Mediterranean.

It is almost perfectly in the middle between the China and Mediterranean Seas, Hiebert says.

Afghanistan's central location on the Silk Road helped develop the region's impressive wealth.

"It was kind of mythical in the past, because it was very wealthy," Hiebert says. "They not only had a lot of agriculture, they had a lot of animal wealth, because the region is really great for herding. And they had mineral wealth."

The wealth and cultural mix of Afghanistan's trading outposts made them popular sites on the Silk Road. Afghan settlements including Tepe Fullol, Ai Khanoum and Bagram were bustling stops for traders. Today Bagram is the site of the U.S. military's Bagram Airfield.

It wasn't only trade goods, however, that moved across Afghanistan. Ideas about trade, religion, communication and politics all mixed on the Silk Road.

The religion Buddhism, for instance, started in India and spread to Afghanistan before migrating to China, Hiebert says.

Bamiyan, in central Afghanistan, was a Buddhist center with towering statues. These dominated local cliffs before they were destroyed by the Taliban government in 2001. The Taliban is a violent extremist group currently fighting the government for control of the country.

"Those giant Buddhas were 60 to 90 meters (200 to 300 feet) tall," Hiebert says. "Those were very easy beacons for traders."

Art, too, developed diverse influences. Greek architectural style, for instance, is found in the ruins of Ai Khanoum, an archaeological site in modern Afghanistan's northeast. Ai Khanoum was conquered by Alexander the Great, and messages to Greek gods such as Hermes and Heracles have been found on artifacts.

The same wealth that made Afghanistan so attractive to ancient traders also made it a target for takeover by outsiders.

Still, from the Greek forces of Alexander the Great to the British Empire of the 19th century, Afghanistan has proved to be nearly impossible to permanently conquer. The region's climate and landscape have earned it the bitter nickname "Graveyard of Empires."

Afghanistan is straight in the center of Asia, Hiebert notes, meaning it has a continental climate. Its weather is not affected by ocean currents. This means it is "really cold in the winter, and it's really hot in the summer. It's a pretty tough place to be," says Hiebert.

Historically, the region's climate and landscape have also made it difficult for Afghans to unify.

Mountains block off groups from one another. When groups meet in the valleys, there is sometimes fighting, Hiebert says.

New Silk Road

Civil and foreign wars have defined modern Afghanistan for more than 30 years. Still, Hiebert says, he and other archaeologists note how Afghanistan has lived on for 5,000 years.

Afghanistan has the resources to thrive once the country stabilizes, Hiebert says. He points out that one of the largest underground copper deposits in the world was just found there.

The country even has other natural resources that may contribute to a new Silk Road.

"We like to think that the 21st century is the century where those old networks are going to be re-established," Hiebert says. "It's not silk anymore. It's oil and gas."

Still, the archaeologist says, it may take Afghanistan years to recover from its long-running war and chaos.

"Afghanistan is a tough place, but you know what? Europe was tough after World War II," Hiebert says. "How long did it take after four years of social disruption in Europe? It took a long time to repair and recover. How long do you think it will take Afghanistan, that has had over 30 years of civil war? It is not going to happen overnight."