The First Archaeoastronomical Study of the Maltese Temple of Borġ In-Nadur

Abstract

The Maltese island has megalithic temples of extraordinary interest for archaeoastronomy. In literature we find different works that involve most of its archaeological sites. The temple of Borġ in-Nadur, set on the top of a hill by the Marsaxlokk Bay in southern Malta, is less well known than the rest of the others, even though it started off as a major attraction for grand tourists and travellers in the Early Modern and Colonial periods. It was explored in the second half of the 1920s by a team of British archaeologists, led by Margaret Murray, who gradually uncovered the ruins of typical Maltese megalithic temple dated to the 3rd millennium BC. In 2011 the efforts of an international team of scholars brought to the publication of a general reassessment of the evidences about the temple of Borġ in-Nadur and the artifacts collected during its exploration, emphasizing its importance for the Maltese Temple Period. The new picture that emerged has reactivate the research around the Borġ in-Nadur temple attracting for the first time the interest of scholars in archaeoastronomy. The archaeoastronomical study of the Borġ in-Nadur’s archaeological site is the first of its kind, as the archaeological remains were put into evidence in 2010, and pays particular attention to the temple. At the moment it is difficult to determine the exact plan of the entire temple, and therefore its axes, but the apsidal building and the main entrance are quite intact. Although this research is at its early stage of development, with regards to archaeoastronomical issues and features related with the temple of Borġ in-Nadur some preliminary considerations can be put forth.

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1 Introduction

About 20 megalithic sites are known in Malta and Gozo and together they probably represent the most relevant tourist attraction of the archipelago and the backbone of the Maltese archaeological scientific literature. However, the temple of Borġ in-Nadur, set on the top of a hill by the Marsaxlokk Bay in southern Malta, is less well known than the rest, even though it started off as a major attraction for grand tourists and travellers in the Early Modern and Colonial periods. It was explored in the second half of the 1920s by a team of British archaeologists, led by Margaret Murray, who gradually uncovered the ruins of typical Maltese megalithic temple dated to the 3rd millennium BC.

The excavations uncovered a monumental sacred complex, characterized by a singular plan including a megalithic enclosure with different cult places. A large number of finds were unearthed, demonstrating the wealth of the community using the site. At that time, the conditions of the temple building were rather good. The preliminary reports of the explorations, published promptly in 1923, 1925, and 1929, were accompanied by a thorough drawn and photographic documentation including an accurate measurements of nearly all megaliths (Murray 1923, 1925, 1929).

2 The Temple of Borġ in-Nadur

The site of Borġ in-Nadur is set on a hill on the St. George Bay, and is comprised of two different settlements: the Bronze Age fortified village on the top of the hill (Tanasi and Vella 2015) and the megalithic temple on the eastern slope that was in part reused and modified throughout the Tarxien and Borġ in-Nadur periods (Tanasi and Vella 2011) (Fig. 1).

Fig. 1

Plan of Borġ in-Nadur site with indication of the Bronze Age settlement and of the megalithic temple (after Trump 1961)

Murray’s investigations revealed the following remains: an Apsidal Building, an Open Area or Main Enclosure, the Field Stones and a Double Chapel (Figs. 2, 3 and 4). The Apsidal Building is a four-apsed temple with a shallow niche at the end. The Open Area or Main Enclosure lies outside the temple and a good part of the megalithic wall was uncovered by excavation. The Apsidal Building can be safely identified as a ‘temple’ on the basis of the similarities in ground plan with other sites. The megalithic set-up of the Open Area, then, could have defined the temple forecourt already in the Temple period. The arrangement is not dissimilar, in fact, to what artists recorded beneath the temple complex at Ġgantija, Gozo, in the nineteenth century. The façade of the Main Enclosure was marked by the sequence of four elements, a monumental main gate, a great menhir and a dolmen (Fig. 5).

Fig. 2

General plan of Borġ in-Nadur temple (Tanasi and Vella 2011)

Fig. 3

The temple at the time of Murray’s excavations (Murray 1929)

Fig. 4

The Apsidal Building and the Main Enclosure from West (photo authors)

Fig. 5

Detail of the outer wall of the Main Enclosure, from East: (1) main gate; (2) the great menhir; (3) the broken dolmen (photo authors)

Along the northern wall of the Main Enclosure, the fourth orthostat shows a large e perfectly circular artificial hole passing through it and a triangular niche with three half spherical sockets carved on the outer surface (Fig. 6).

Fig. 6

The fourth orthostat of the outer wall of the Main Enclosure (photo authors)

Another smaller enclosure very poorly preserved, named Field Stones, was probably located to the North of the main complex, and a second apsidal building closed by a smaller precinct, called the Double Chapel, was explored to the South-East. Groups of objects including pottery sets, loom weights, and also an anthropomorphic betyl idol (Fig. 7), found in different areas of the Double Chapel and related to Bronze Age period may suggest cultic activities still active during the Bronze Age at least in this part of the complex.

Fig. 7

Betyl idol from the Double Chapel (Veca 2011)

In the past 80 years, for different reasons this site was forgotten and generally neglected with the result that the current conditions of the entire archaeological area are unfortunately rather poor.

Due to the phases of occupation subsequent to Temple period, many megalithic elements were removed from their original positions and completely de-functionalized and decontextualized. That especially affected betyls, menhirs and the so called notched stones (Figs. 8 and 9).

Fig. 8

Menhirs incorporated in the fortification wall of the Bronze Age settlement (photo authors)

Fig. 9

Fragment of notched stone re-employed for the construction of a later wall (photo authors)

This has jeopardized the interpretation of the general organization of the complex and as a consequence, Borġ in-Nadur has not been included in any tourist itinerary and its role in Maltese prehistoric has been always considered marginal.

Against this scenario, in 2011 the efforts of an international team of scholars brought to the publication of a general reassessment of the evidences about the temple of Borġ in-Nadur and the artefacts collected during its exploration (Tanasi and Vella 2011), emphasizing its importance for the Maltese Temple Period. The new picture that emerged has reactivate the research around the Borġ in-Nadur temple attracting for the first time the interest of scholars in archaeoastronomy, a discipline which has recently proved to have a fertile field of application in prehistoric Malta (22th SEAC Conference, Malta 21–27 September 2014).

In particular, the production of a virtual interactive reconstructive model in 3D computer animation of the temple has resulted instrumental for the reactivation of the research about this monument (Tanasi and Stanco 2013). The temple has been rebuilt using the measurements provided in Murray’s reports, while all the other structures were reconstructed using dimensions recorded on site or through comparisons with other temple sites (Figs. 10, 11 and 12).

Fig. 10

Virtual interactive model of the Apsidal Building (Stanco and Tanasi 2013)

Fig. 11

Virtual model of the Main Enclosure (Stanco and Tanasi 2013)

Fig. 12

Virtual model of the fourth orthostat of the outer wall of the Main Enclosure (Stanco and Tanasi 2013)

The reconstruction work has been completely carried out using the Blender 3D suite,¹ an open source cross-platform software for modeling, rendering, animation, postproduction, creation, and playback of interactive 3D contents. The 3D model was not intended to reconstruct in elevation the missing parts of the temple but was aimed at rediscovering digitally what was found by the archaeologists nearly 80 years ago. In order to add realism to the digital replica, a study of light sources was carried out, simulating a complete cycle of the sun on mid-summer day through the use of the Radiance raytracer² (Fig. 13).

Fig. 13

Virtual study of the effect a solar cycle on the shadows produced by the megaliths of the Borġ in-Nadur temple (Stanco and Tanasi 2013)

3 Archaeoastronomy in Malta

The Maltese island has megalithic temples of extraordinary interest for archaeoastronomy. In literature there are several works about such sites. Among them, it must certainly be remembered the contributes of Agius and Ventura (1981) and Foderà Serio et al. (1992). Agius and Ventura’s was the first work considering the possible astronomical alignments of the Maltese temples. The study applied a maximal approach: for axis of the temple it was considered just what was clearly a feature of the construction, even if it was not a true axis of symmetry.

Out of 26 azimuths, there was a clear concentration of 20 of them between 128° and 230°, between SE and SO, while the remaining 6 showed no patterns (Fig. 14).

Fig. 14

The table shows azimuth and declinations of the temples’ axis (from Agius and Ventura 1981)

In their analysis of the data, the authors of the first work considered the rising and setting positions of the Sun at solstices and equinoxes and of the Moon at standstills. Moreover they studied the alignment of a number of temples towards the rising or setting positions of some bright stars: Sirius, α Crucis, α Centauri and β Centauri, α Lyrae and α Ursa Majoris.

In the work of Foderà Serio et al. (1992), it was applied instead a minimal approach: for axis of the temple it was considered just what was an unequivocal axis of symmetry. In this case just 15 azimuths were measured (Fig. 15), and the authors took into account mostly the possible alignments of the temples at sunrise or setting positions of some bright stars: Sirius, Canopus, α Crucis, β Crucis and γ Crucis, α Centauri and β Centauri, and The Pleiades.

Fig. 15

The orientations’ diagram with the azimuth of the temples’ axis (Foderà Serio et al. 1992)

4 Archaeoastronomy at Borġ in-Nadur: Preliminary Analysis

Due to the scarcity of previous data, the archaeoastronomical study of the temple of Borġ in-Nadur is the first of its kind and obviously the study is in its infancy. Without a proper survey and technical analysis on-site, it is difficult to determine the exact plan of the entire temple and in particular its axes, although but the Apsidal Building and the main entrance are quite intact. From an initial examination with satellite data, it was found that the azimuth of the apsidal building is 125°, then framed in the angular range determined by Agius and Ventura, while the azimuth of the main entrance is 107° (Fig. 16). The temple of Borġ in-Nadur has several characteristics that make it unique, as the many standing stones and the peculiar location of the dolmen in the wall of the Main Enclosure.

Fig. 16

Borġ in-Nadur. Satellite view of Temple, with the Google Earth ruler showing the azimuth of the building (Image courtesy Google Earth, drawing by the authors)

The first step in the research agenda will be a fieldwork already scheduled for Spring 2018, aimed to acquire all the missing technical data and to start comparing them with those already available for the other megalithic temples. Using the technological support of the Center for Virtualization and Applied Spatial Technologies (CVAST) of University of South Florida, a terrestrial and aerial LIDAR scanning of the Borġ in-Nadur temple will be carried out.

3D scans will be georeferenced and complemented as needed by digital photogrammetry, and the assembly of all digital georeferenced data will be built into a GIS environment. Laserscanning data will be collected at a nominal minimal resolution of 5 cm across the entire study area and areas of special interest will be collected at a nominal minimal resolution of 1 cm. Digital photogrammetric products will be produced at comparable resolutions. Georeferencing data as needed will be collected using dGPS to ensure the locational accuracy of the data. dGPS data will have a minimal accuracy of 0.2 m. All data will be transformed into UTM projections. Deliverables will be registered and georeferenced point clouds for each study site together with appropriate metadata and a report detailing the project plan and workflow. Point clouds will be delivered in the .las or .laz format. The GIS will consist of publicly available satellite or aerial photographic base imagery, the georefenced point clouds, and annotations attached to vector features that will guide a user.

The Maltese site presents the same architectural features and setting of the Bronze Age site of Motilla del Azuer in Castilla-La Mancha (Spain), 3D captured by CVAST scientific team in 2016. The digital outcome, currently available for scholars and general public in the CVAST Sketchfab collection,³ has an excellent level of quality that makes it a valuable interpretative tool.

Once the capturing phase will be completed, during the data processing it will be possible to generate a high quality ortophotograph from which it will be extracted a new updated plan of the entire complex. Through the segmentation of the entire 3D model, each single architectural element will be converted into an individual 3D model which can switched on or off. This breakdown of the model into 3d layers will give the opportunity to create a simulated environment in which for example megaliths added in a later phase or moved from their original position can be switched off in order to achieve a plan of the complex closest to its original design.

This new and innovative data set will represented the testing ground for the above mentioned hypothesis and the starting point a new archaeoastronomical interpretation for the temple of Borġ in-Nadur.

5 Conclusions

The archaeoastronomical reappraisal of the temple of Borġ in-Nadur at first glance promises to provide interesting data which will prove once again the profound knowledge of the ancient Maltese people for the natural phenomena, the solar cycle and the stars. This study never carried out before already represents an important novelty that however just enlarge an existing data set of cases study.

A game changing novelty, instead, could come by the contextualization of a new archaeoastronomical evidence in the frame of the reuse of the Borġ in-Nadur in the Middle Bronze Age, where all around it was established a settlement surrounded by megalithic and gargantuan walls (Tanasi and Vella 2015). The outstanding defences of the temples, cannot be archaeologically explained as there are not traces of external threats of internal competing forces. In particular, the massive D-shaped bastion (see Fig. 1), does not have comparison in the megalithic architecture of the Bronze Age Mediterranean, from Syros in the Aegean to Los Millares in the Balearic archipelago. Would it possible to hypothesize that the ruins of the ancient temple empowered by its astronomical connections justified the plan and the development of the Bronze Age settlement? Would it be possible to infer that unique fortification without equals was meant to protect and keep safe those ruins? Finally would it be possible to explain the unusual feature of the D-shaped bastion calling in reasons connected to a lost astronomical knowledge?

These rhetorical questions, on one side, are obviously meant to provoke but on the other side they inform us about how complex the archaeoastronomical reappraisal of Borġ in-Nadur as site can become and long is still the way that takes us to the stars.