Built more than 1,000 years ago in the middle of a vast sea of sand dunes, nobody knows for certain who constructed this mysterious circular fortress. This is Ksar Draa in Algeria—an ancient architectural wonder whose true origins have been completely lost to history. Ksar Draa is located near Timimoun in Algeria’s vast Sahara Desert, one of the most remote inhabited regions in North Africa. The site is remarkable not only for its distinctive circular design, but also because historians still debate who built it and exactly when. Most estimates date its origins to between the 10th and 12th centuries, though some researchers believe portions of the structure could be even older. The term ksar refers to a fortified settlement commonly found across the Maghreb. These communities served as defensive outposts, trade hubs, and safe havens along the trans-Saharan caravan routes. For centuries, merchants transported gold, salt, ivory, textiles, and enslaved people across these networks, connecting sub-Saharan Africa with Mediterranean markets. Unlike most Saharan settlements, Ksar Draa’s unusual circular layout makes it especially distinctive. From above, it resembles a giant wheel set into the desert. Thick outer walls helped protect its inhabitants from raids, while a network of interior rooms and passageways provided storage and shelter from the region’s extreme heat. Today, shifting sands continue to engulf parts of the ruins, and much of its story survives only through oral tradition, making Ksar Draa one of the Sahara’s most intriguing and least understood archaeological sites. Although it is often described online as a “lost fortress,” Ksar Draa was known to regional travelers for centuries. The real mystery is not its existence, but the identity of its original builders and the exact role it played within the medieval trans-Saharan trade network.(Historic Vids)