In the largest study of north-western Arabia’s mustatil to date, archaeologists have recorded more than 1,000 of the enigmatic rectangular structures across 200,000km2 of land, shedding light on one of the oldest widespread monument-building traditions.
These prehistoric structures take their name from the Arabic word for ‘rectangle’, and while they were first recorded in the 1970s, the recent survey, carried out by a team led by Hugh Thomas from the University of Western Australia and funded by the Royal Commission for AlUla, found there were nearly twice as many mustatil as previously thought.
As well as documenting sites from the air, the archaeologists explored around 40 of the sites on the ground, and excavated one, revealing important evidence about their organisation and possible use. The results of the fieldwork, recently published in Antiquity, established that the monuments were more complex than previously known. Ranging in length from 20m to some 600m, mustatil have a head (which is often placed on a higher elevation than the rest of the structure), a courtyard, long, low walls, and a base, with a narrow entrance way, through which people would have had to proceed single-file. The overall architecture seems to encourage procession. Sometimes, immediately in front of the base, there is a set of circular cells, often with a standing stone in the centre of the cell.

Recent work has already suggested that mustatil were used for rituals. This line of thinking is supported by finds from the new fieldwork. In 2019, the team began excavating an undisturbed monument. Inside the central chamber of the head, they found the remains of sheep or goat, gazelle, and mainly cattle, around a large upright stone in the centre of the chamber. Significantly, the unearthed cattle remains also provided material for radiocarbon dating. One horn and one tooth were dated to around 5300-5000 BC, presumably when they were deposited in the monument. These dates make mustatil part of one of the oldest-known monument-building traditions.
This is the earliest evidence, too, for a cattle cult in the Arabian Peninsula. Melissa Kennedy from the University of Western Australia, assistant director of the project, explained, ‘As yet we don’t know why these animals were sacrificed, perhaps they were offered to garner the favour of the gods. We know that cattle played an important role in the lives of the Neolithic people of this region, with scenes of cattle and cattle herding found across the rock art of north-west Arabia. The types of cattle offerings are similar to what has been found in southern Arabia, although the evidence from mustatil is about 900 years earlier. However, the way these two cattle cults were expressed is very different, suggesting a distinct but related phenomenon.’
Mustatil were built all across the landscape. Those on the slopes of hills tended to be visible from a great distance, while those on top of sandstone mesas were less visible but offered expansive views. Each of these types of location points to the importance of views both of and from the monuments. Sometimes, mustatil were found in clusters, but the reasons for this remain unclear. Kennedy said, ‘We aren’t really sure why they were built in groups yet, but there are a number of possibilities. Groups of mustatil may represent successive phases of use. Perhaps they could only be used for a limited time before a new structure needed to be built? They could also represent different social groups attempting to mark the landscape. These are just a few of the possibilities.’