Ancient EgyptIn an incomparable setting, next to the western bank of the River Nile, stands the hill on which rises the Dome of the Winds (Qubbet el-Hawa). This privileged place was used for several centuries (mainly during the Old and Middle Kingdoms) to bury some of the prominent governors of the southernmost region of Egypt, their household staff and officials. Currently, this group of funerary structures, based on hypogea (underground tombs), is known as the necropolis of Qubbet el-Hawa. The hill is quite close to the modern city of Aswan, located on the opposite bank of the river, and to Elephantine island, situated above the First Cataract, where ancient Egyptians established the capital of the first nome of Upper Egypt.
The geological and topographical conditions of the hill favoured the construction of dozens of hypogea of different characteristics, adapted to the customs and possibilities of the time and, mainly, to the power of the deceased. Most of the tombs were later desecrated and reused for burial or other purposes – for example, a community of Coptic monks used several ancient structures as churches and other monastic places. On the other hand, some funerary structures have survived intact to the present day, providing important information about their owners and the funerary rituals used at that time.
Geomatic work
Most of the funerary structures of the necropolis of Qubbet el-Hawa have been studied during the last decades, allowing data such as their geometry, construction, owners, and evolution to be determined. Some of the most recent findings have been carried out by the team of the Project Qubbet el-Hawa, led by the University of Jaén (Spain) and directed by Alejandro Jiménez-Serrano. Since 2008, this project has studied some of the main funerary structures of the necropolis, finding a number of intact burial chambers, and providing a large amount of new data related to archaeological, anthropological, and architectural aspects.
Some of the tasks developed by the team are related to obtaining complete documentation of the geometry of the funerary structures and, consequently, the analysis of their spatial behaviour independently and jointly, considering their interrelationships within the hill. This involves the use of geomatic techniques (methods and technologies used to collect, analyse, and present geographic data) that include photogrammetry (creating 2D and 3D models from photographs) and LiDAR (a remote-sensing method using pulsed laser light to measure ranges). The application of current geomatic techniques is essential to obtain reliable metric documentation of these structures with sufficient accuracy to support archaeological and architectural studies. In these cases, it is common to use geomatic products such as topographic maps, sections, 3D models, and orthoimages (which are geometrically corrected aerial and satellite photographs).
The geomatic work developed at Qubbet el-Hawa by Antonio Tomás Mozas Calvache, José Luis Pérez and José Miguel Gómez from the University of Jaén has been technically challenging because of the nature of the structures at the site, which are composed of narrow spaces and vertical shafts up to 13 metres deep. In addition, it was necessary to reference all data to a global coordination reference system (WGS 84, used by GPS, is an example of such a system) to allow accurate geo-positioning of each funerary structure. This is a difficult task for the deepest and narrowest parts of each tomb, which have to be geo-referenced through a surveying network linked to the exterior.
QH31, QH32 and QH33
During the last few years, geomatic work has focused on three of the largest and most impressive funerary structures in the necropolis: QH31, QH32, and QH33, all dating to the Twelfth Dynasty (c.1985-1795 BC). These are adjacent hypogea (their entrances about 20 metres apart), located in the central area of the necropolis, on a slope oriented to the south-east. QH32 is dated to the reign of Senusret II, and experts suggest that it was the tomb of Khema, the governor of Elephantine. After that, QH31 was constructed between the reigns of Senusret II and Senusret III, by the governor Sarenput II, son of Khema. QH33 is dated to the end of the reign of Senusret III or the earliest years of Amenemhat III, and is thought to have belonged to Heqaib-ankh, with a secondary burial chamber for his stepbrother Heqaib III (grandson of Khema).
This sequence is at odds with the order in which the tombs are set out, as the first tomb to be built is between the two later tombs. However, QH32 was constructed at a higher level, suggesting that the other two were perhaps constructed where geological conditions were more favourable lower down.
The structures are composed of external (courtyard) and internal (hypogeum) zones. The courtyards were excavated on the slope, generating a façade that separated the external and internal zones. In all cases, the courtyards form the entrance to each complex, although they were never completed, probably due to the sudden death of their owners, or political changes. The hypogea were excavated into the rock and are complex structures composed of several spaces, such as halls of pillars, corridors, vertical shafts, and burial chambers. They are large, too, reaching lengths of 22-32 metres, widths of 10-23 metres and heights of 9-18 metres.
Incredible accuracy
The geomatic work focused on obtaining realistic 3D models using a combination of techniques integrating photogrammetry and terrestrial laser-scanning (TLS or LiDAR). Thousands of photographs and hundreds of scans were taken to obtain a complete point-cloud of each structure, each made up of millions of points. These models were geo-referenced globally through a surveying network inside all the tombs, connected to the outside. Therefore, all the 3D models are positioned virtually in their real location in space with great accuracy, allowing experts to compare their spatial relationships.
When visualising these 3D models, one of the most impressive aspects is the distribution of the three tombs inside the hill. The different structures meander from their entrance to the final burial chamber, and yet, in spite of being so close, together they do not cut across each other. The 3D models of QH32 and QH33 show that the two tombs come within 10 centimetres of each other in two different areas. This startling proximity demonstrates the great accuracy achieved by the ancient Egyptians when constructing these complexes. It is clear that they considered the spatial distribution of the first excavated tomb before excavating the second one. Evidently, the construction followed some kind of plan or sketch, with measurements and directions, similar to the papyrus plan of the tomb of Ramesses IV from Turin’s Museo Egizio.
Another remarkable geometric aspect shown by the 3D models is the spatial relationship between the sanctuary and the main burial chamber. In both QH32 and QH33, the burial chamber is almost directly under the sanctuary (9 metres and 13 metres deep respectively), so that the deceased lay just a few metres beneath their statue in the sanctuary where offering rituals took place.
Orientation
The geomatic work allowed engineers to determine the main orientation of these funerary structures using both surveying techniques and 3D models. Initially, the objective was to determine if their axes were parallel. Visually, it can be observed that the plane of the façades of QH31 and QH32 are more or less continuous, while the zone related to QH33 shows a slight turn. Analysis of the orientation of axes showed that those of QH31 and QH32 are almost parallel (with a deviation of only about 1°), while the axis of QH33 has a deviation of about 7° with respect to the others. These facts and other geometric clues suggest the orientation of QH33 was intentionally different from that of the other tombs.
It is known that ancient Egyptians had a special relationship with the sun and other stars that were considered gods. Therefore, experts compared the azimuth (angle from the north) of the main axis of each tomb to the azimuth of the sun and other stars during certain astronomical phenomena occurring at the time the tombs were constructed. In the case of QH33, the coincidence was almost perfect with two astronomical events. The first was the winter solstice sunrise at that position, which had a deviation of less than 1°. In addition, this orientation coincided (again with a deviation of less than 1°) at this position with the azimuth of the heliacal ascent of the star Sirius (the god Sopdet or Sothis), the brightest star in the night sky, which became visible above the eastern horizon just before sunrise. This event preceded the usual flooding of the Nile and was used to set the ancient Egyptian calendar. This implies that, to define the main axis of this tomb, the builders used two important astronomical phenomena that had an azimuth difference of less than 2°. In fact, the azimuth of the QH33 axis is approximately between both azimuths (sun solstice and heliacal ascent of Sirius).
Therefore, it was more important for both of these astronomical phenomena to be visible from the sanctuary, where the statue of the deceased stood, than to try to keep the façade in line with that of the other two tombs. This again confirms the high degree of precision achieved in the construction of this funerary monument.
Precise geometry
The analysis of the 3D models has also allowed engineers to calculate the proportions of the structures, and the flatness, inclinations, parallelism, and perpendicularity of the walls, which once more show the incredible precision achieved by the ancient builders. For example, in the hall of pillars in QH31 and QH33, the ratio of length to width is equal to the square root of two, and width to height is equal to the square root of three. However, the most interesting results were obtained when completely analysing the public areas (composed of entrance, hall of pillars, corridor, cult chamber, and sanctuary). In this case, the engineers found the length of the public areas are equal to 3.5, 3, and 2 times the width of the hall of pillars in QH31, QH32 and QH33 respectively. This implies that the builders attempted to create an artistic sense of harmony in this area.
The study of the flatness of walls was carried out by analysing the deviations of the point-cloud related to each wall with respect to a fitted plane. The results in the case of the sides of the pillars are impressive, because the distances from the points to the fitted planes are less than 1 centimetre, showing a great degree of flatness.
The analysis of wall inclinations (based on the fitted planes) showed that the walls in the halls of pillars and sanctuaries had deviations of less than 0.5° from the vertical, while the halls of pillars also showed high degrees of parallelism between opposite walls, and perpendicularity between adjacent walls, achieving deviations of less than 0.1°.
In praise of ancient builders
In conclusion, the geomatic work carried out in these funerary structures has allowed engineers to obtain important information about a large number of geometric aspects of their construction. The results confirm the existence of prior planning (as revealed by the absence of cross-overs despite their proximity) and detected orientation intentionally determined to coincide with two astronomical events and specific ratios applied to certain dimensions. In addition, the geometric study shows that the tomb-building work was carried out with great precision thanks to the skill of the builders in setting out measurements, excavating the various spaces without deviations, and defining walls that were almost exactly vertical and very well polished, especially in the hall of pillars and sanctuary.
Antonio Mozas, Jose Luis Pérez, and José Miguel Gómez are researchers at the University of Jaén (Spain). They specialise in the application of photogrammetry, cartography, and surveying to heritage, and have published a large number of scientific articles and conference papers on this topic. They have worked at several archaeological sites, mostly in Spain, although their main interest is currently focused on the Egyptian tombs of the necropolis of Qubbet el-Hawa (Aswan).
Further reading:
A Jiménez-Serrano (2023) Descendants of a Lesser God: regional power in Old and Middle Kingdom Egypt (American University in Cairo Press).
A T Mozas-Calvache el al. (2022) ‘Geometrical study of Middle Kingdom funerary complexes in Qubbet el-Hawa (Aswan, Egypt) based on 3D models’, Virtual Archaeology Review 14(28): 1-18.
All images: the authors, unless otherwise stated
