The Silk Road was a famous trade route. It was an ancient network of roads and trading posts. It linked Asia and regions along the Mediterranean Sea.

As traders traveled on the Silk Road, many passed through the country we now call Afghanistan.

Afghanistan is a land of rugged mountains. Yet this threatening landscape actually helped ancient traders, says Dr. Fredrik Hiebert. He's a National Geographic Society archaeology expert. Archaeologists study objects from long ago.

All those mountains mean there are valleys. Valleys are like natural trails. It was easy for traders to follow along the valleys and rivers, Hiebert notes.

Graveyard Of Empires

Afghanistan sits almost right in the middle between the China Sea and Mediterranean Sea. It connected the empires of Asia, eastern Africa and southern Europe. Traders and travelers on the Silk Road could interact with people from China, India, Persia, Arabia, eastern and North Africa and the eastern Mediterranean.

Afghanistan's central location on the Silk Road helped it become rich. It had farming products, minerals and animals to trade, Hiebert says. The settlements Tepe Fullol, Ai Khanoum and Bagram were popular stops in Afghanistan for traders.

More than just goods moved across Afghanistan. Ideas about trade, religion and government all were exchanged on the Silk Road.

Buddhism, for example, started in India. It spread to Afghanistan. Then it moved on to China. Bamiyan, in central Afghanistan, was a Buddhist center. It had towering statues of Buddhas on high cliffs. "Those giant Buddhas were 60 to 90 meters (200 to 300 feet) tall," Hiebert says. They were easy for traders to see, he notes.

The statues were destroyed by the Taliban in 2001. The Taliban is a violent extremist group currently fighting the government for control of the country.

Art, too, was influenced by different cultures. Greek architectural style, for example, is found in the ruins of Ai Khanoum. This archaeological site is in northeast Afghanistan. Ai Khanoum was conquered by Greek king Alexander the Great. Messages to Greek gods have been found on artifacts.

Afghanistan's wealth also made it a target for takeover.

Still, Afghanistan has been nearly impossible to conquer. Alexander the Great could not conquer it. The British Empire failed to take it over during the 1800s. The region has been called the "Graveyard of Empires." It got this nickname because its harsh climate and landscape made it impossible for empires to conquer.

Afghanistan is "really cold in the winter, and really hot in the summer. It's a pretty tough place to be," says Hiebert.

The region's climate and landscape have also made it difficult for Afghans to come together. Mountains block off groups from one another. When groups meet in the valleys, there is sometimes fighting, Hiebert says.

New Silk Road

For the past 30 years, Afghanistan has been torn apart by war. Still, Hiebert notes, Afghanistan has still survived for 5,000 years.

Afghanistan has the resources to thrive once the country gets stable, Hiebert says. He points out that large amounts of underground copper were recently found there.

The country even has other natural resources. Could a new Silk Road be coming soon? Hiebert thinks that old trade partnerships could be established again. However, the main good being traded would not be silk anymore, he says. "It's oil and gas."

Still, Hiebert says it could take years for Afghanistan to heal from the war there.

"Afghanistan is a tough place, but you know what? Europe was tough after World War II," he says. After four years of war in Europe, he says, "it took a long time to repair. 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."