Here’s what you’ll learn when you read this story:

• A satellite survey of the Atbai Desert between the Nile River and the Red Sea pinpointed 280 monumental burials, including 260 that were previously unknown.
• Researchers believe the 6,000-year-old sites belonged to a lost pastoral culture that focused heavily on cattle.
• Human and cattle remains were often interred alongside each other inside the circular stone structures.

Roughly 6,000 years ago, a culture of cattle herders roamed the harsh Atbai Desert, between the Nile River and the Red Sea in eastern Sudan. Researchers have located 280 stone burial monuments that attest to their existence. The tombs open a window into a lost moment in history when humans shared a unique connection with cattle.

Using satellite imagery, an international team identified the 280 structures, 260 of them previously unknown. Spanning the desert, they all share a common monumental burial design typified by circular stone enclosure walls, according to a study published in the African Archaeological Review.

“Despite being at the crossroad of the well-studied worlds of ancient Egypt and Nubia, the archaeology of the Atbai Desert, the region between the Nubian Nile and the Red Sea, is still in its infancy,” the authors wrote. “This monumental feature, a local manifestation of common Saharan prehistoric burial practice, while exhibiting diverse architectural features, presents a consistent burial tradition across the entire desert expanse between the Nile and Red Sea.”

The monuments, which have been dubbed Atbai Enclosure Burials (AEBs) by the archaeologists who found them, have been dated to between 4500 and 2500 B.C.E. and measure up to 60 feet in length. Researchers opted to use satellite imagery to investigate the 175,000 square miles of desolate terrain around them due to the remote and dangerous nature of fieldwork in the war-torn country. The burials feature large, circular enclosure walls made with local stone surrounding internal burial chambers. “This tradition appears to be largely confined to the Atbai Desert, but there are rare cases of similar structures near the Nile Valley,” the authors wrote.

The monuments were typically located at the bases of mountains and plateaus, or near watering spots. “The fact that many of the burials are specifically located in favorable topographic situations for accessing water,” the authors wrote, “rather than being evenly apportioned across the desert, suggests that the ancient habitants deliberately constructed AEBs near conducive water sources. Broadly, the location of AEBs can be taken as an index of favorable areas for pasturing and watering, and thus pastoralist habitation.”

The importance attached to cattle is the most noticeable characteristic of the burial monuments. Cattle are prominent features in the rock art near the tombs, and the remains of cattle have repeatedly been found in excavations of the burial sites. The archaeologists hypothesize that the cattle remains were placed alongside human burials as part of a funerary ritual.

The pastoral community’s close interaction with cattle was illustrated by livestock tracks seen worn into the plains and water sources near the burial monuments. These monuments must have had great importance as social markers, given that the mobile cattle herders would need to pause their movements to construct stone architecture. And the monuments are unique—the authors claim the style is distinct enough from other Nile Valley cultures to have its own character.

Environmental causes explain the rise and demise of the tomb-building tradition. The culture emerged during the African Humid Period and ended as the monsoon rains shifted south, reducing grazing land. The drying and loss of water sources made cattle raising impossible. The desert won and the herders were forced to the south, preventing additional monumental burial traditions from entering the landscape. The newly discovered tombs are remnants of a lost culture that was likely erased by a shifting environment.