At a Glance

Hasankeyf is thought to be one of the oldest continuously inhabited settlements on Earth.Historical treasures at the site include ruins of a 12th-century palace and a mosque built in 1409.The area will be underwater when the Ilisu dam project comes online.

A 12,000-year-old settlement on the banks of the Tigris River in Turkey that was once a stop on the Silk Road will soon be underwater.

The town of Hasankeyf is one of about 200 settlements that will be lost as the reservoir behind the new Ilisu dam is filled over the next few months.

Residents have been told they must be gone by Oct. 8.

"We were living with hope but we lost that now. They gave us three to five months," Firat Argun, whose family has lived in Hasankeyf for 300 years, told CBS News. " I feel like I have just arrived in this world. I don't know if it is going to be good or bad."

Ridvan Ayhan was born in one of the thousands of caves that line the cliffs overlooking Hasankeyf.

“It’s not just our story, Hasankeyf, it’s also your story, because,” Ayhan, who is also an active member in the Initiative to Keep Hasankeyf Alive, told The Guardian.

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The townspeople and environmentalists, archaeologists and other activists from around the world have spent years trying to block the dam's construction. They say the dam will cause irreversible cultural and environmental damage.

A view of the construction work along the Tigris River that runs through the 12,000-year-old Hasankeyf settlement and ancient citadel town that will soon be submerged by the waters of the nearby Ilisu dam in southeastern Turkey.

(Yasin AKGUL/AFP/Getty Images)

Hasankeyf is thought to be one of the oldest continuously inhabited settlements on Earth, according to The Guardian. Its earliest inhabitants carved thousands of caves in the limestone cliffs during the Neolithic era.

Included among the 20 cultures that have influenced the settlement are the Romans, Byzantines, Mongols and Arabs. Marco Polo may have crossed over the stone, brick and wooden , according to Smithsonian.com. Only two massive stone piers and one arch remain.

The Ottoman Empire absorbed the town in 1515, and Hasankeyf has since been part of modern Turkey.

Historical treasures at the site include ruins of a 12th-century palace, a mosque built in 1409 by the Ayyubid Sultan Suleiman; and the 15th-century cylindrical Tomb of Zeynel Bey.

The tomb is one of only eight historical monuments that have been saved, The Guardian reported. They have been moved to the site of a new settlement about a mile and a half away called New Hasankeyf. The new town has , CBS News reported.

The tomb of Zeynel Bey, front, and the Artuklu Hamam, a centuries-old bathhouse, are two of only eight historic monuments to be saved in Hasankeyf, Turkey, from the Ilisu dam project.

(Ilyas Akengin/AFP/Getty Images)

Environmentalists fear losses to the natural environment will be permanent, too.

“The Tigris river basin is without having been dammed,” environmental engineer Ercan Ayboga, who is also part of the Initiative to Keep Hasankeyf Alive, told The Guardian. “The dam will completely destroy the river banks. The microclimate will change due to the dam, a phenomenon we have already seen after the dams on the Euphrates. The biodiversity will suffer; the rich variety of plant and animal life will be severely diminished.”

Toon Bijnens, international coordinator for the Save the Tigris and Iraqi Marshes Campaign in Sulaymaniyah, said he expects water levels to decrease downstream by 40%.

“There will be increased salt water intrusion, making the water unfit for drinking or irrigation,” Bijnens told The Guardian.

He also said a considerable part of the Mesopotamian marshes in southern Iraq, which were once dammed by Saddam Hussein in the 1990s, will dry up.

Activists sought and failed to get the Turkish government to seek UNESCO protected status for Hasankeyf as a site of significant historical importance. Court fights in Turkey have been unsuccessful, and a final bid at the European Court of Human Rights was dismissed this year as "inadmissible," CBS News reported.

The dam was first conceived in 1954. Legal battles delayed ground-breaking until 2006. When it is completed, the dam is predicted to generate 4,200 gigawatts hours of electricity annually.