From his roof, Sidi Mohamed Lemine Sidiya scans the mediaeval town of Oualata, a treasure that is disappearing under the sands of the Mauritanian desert.

"It's a magnificent, extraordinary town," said Sidiya, who is battling to preserve the place known as the "Shore of Eternity".

Oualata is one of a UNESCO-listed quartet of ancient, fortified towns or "ksour", which in their heyday were trading and religious centres and now hold jewels dating back to the Middle Ages.

Doors crafted from acacia wood and adorned with traditional motifs painted by local women still dot the town.

Centuries-old manuscripts, a rich source of cultural and literary heritage handed down through the generations, are also held in family libraries.

But the southeastern town near the border with Mali is vulnerable to the ravages of the Sahara's extreme conditions.

In the punishing heat, piles of stone and walls that are ripped open bear witness to the impact of the latest, especially heavy, rainy season.

"Many houses have collapsed because of the rains," Khady said, standing by her crumbling home, which she inherited from her grandparents.

An exodus of people leaving Oualata only compounds the problem.

"The houses became ruins because their owners left them," said........

© International Business Times