**3. Cultural Astronomy in Action: Vall Bohí Medieval Churches**

It should be useful to include the description of a case study, where a series of sites can be sampled, in order to illustrate the aforementioned issues. In this sense, we present in this section a site where the local landscape, the distant horizon and the skyscape could interact, but at the same time would allow preserving the spirit of cultural astronomy as a sustainable discipline which respects the environment.

Located at the foothill of the Pyrenees, the secluded and beautiful Bohí Valley gained a significant relevance from the 9th century onwards. After the Muslim conquest of the Iberian Peninsula, some Christian counties were formed at the valleys of the Pyrenees with the support of the Carolingian kings. Apparently, the local feudal lords of this area received a significant amount of money to support the conquest of Saragossa and other nearby populations and they used such income for building a number of churches between the 11th and 12th centuries [36].

Nine of them remain in the area, all of them built in a Romanesque style with strong Lombard influences. They present elegant mason work and tall and stylized towers and the interior is frequently decorated with elaborate paintings (see Figure 5). These characteristics and their excellent state of preservation granted their inclusion in the UNESCO's World Heritage List in 2000.

According to the canonical medieval sources, the orientation of a church should be such that the apse must be facing towards east, and in particular at the equinox as defined in the Nicaea's Concilium [37]. In previous studies we have verified that, for the Iberian Peninsula, and for the period right before the introduction of the Romanesque style, such a definition is somewhat ambiguous. Pre-Romanesque churches in the Iberian Peninsula are vastly located in the northern half of the Peninsula and are normally facing a few degrees north of equinoctial east [38]. This can hardly be explained by an orienting method where the shadow of a gnomon is used to obtain the orientation of the church. However, a direct observation of sunrise on a given day and the use of the Julian calendar could be a likely explanation. Both the alleged day of the equinox, March 21st, or March 25th, a prominent Christian feast, would move with time as the Julian calendar shifted with respect to the seasons. One interesting exception to the norm for the Iberian Peninsula was found in the Serrablo Valley, where most churches (dating from the 10th century) are facing east but slightly south, instead of

north, of the equinox [38]. Serrablo is not far from Bohí (c. 90 km as the crow flies), and those churches could perhaps be understood as the direct precedents of these ones in Bohí.

**Figure 5.** Top-left, Sant Climent de Taül, at Vall Bohí, is a wonderful example of the Romanesque churches in this mountainous area. Frequently the interior is decorated with magnificent paintings, often depicting astronomical symbolism associated to the Christian cult, such as in Santa María de Taül (top-right). The bottom-left panel shows the orientation diagram for the 10 churches presented in Table 1. Each measurement is plotted as a short stroke inside the circle. The strokes outside the circle indicate the cardinal points and the rise and set of the sun at the solstices for the latitude of the valley. However, this diagram does not take into account the altitude of the horizon, which at this alpine area is quite significant. To account for it, the declination histogram is presented in the bottom-right panel. It shows that, despite the azimuths being mostly towards several degrees south of east, the altitude of the horizon renders the orientations of a significant set of churches closer to equinoctial dates. © J.A. Belmonte and A.C. González-García.

**Table 1.** Orientation data for the nine churches in Vall Bohí, plus one in Andorra (Sta. Coloma). Columns indicate the church name, azimuth as measured towards the church apse, the altitude of the horizon in that direction and the astronomical declination. The mean latitude of the valley is 42◦30 North.


In summer 2011, nine churches in the area included in the UNESCO list (plus Santa Coloma in Andorra la Vella) were measured in a field campaign. Their data are included in Table 1. Measures were obtained using a Silva Survey Master tandem with a professional compass plus a clinometer. Thus, the accuracy of a single measurement can be estimated to be of <sup>1</sup> 4 ◦ in azimuth and <sup>1</sup> 2 ◦ in altitude of the horizon, this translates into roughly <sup>3</sup> 4 ◦ in astronomical declination. No single rock or terrain area was moved when taking the measurements. These where corrected for magnetic declination employing the Enhanced Magnetic Model (EMM) found on the National Geophysical Data Center (NGDC) website (https://www.ngdc.noaa.gov/geomag-web/), the latitude was obtained with a hand-held GPS and astronomical declination was calculated employing our own software including a correction for atmospheric refraction [39].

Figure 5 shows that all churches were facing the east horizon, and all but one were inside the solar limits. In particular, the inspection of Table 1 and the declination histogram in Figure 5 shows that a good number of them were facing slightly south of the equinox, by averaging −3◦ in declination (above 15◦ in azimuth). Interestingly, the 14◦ of altitude of the close horizon at Sant Joan de Bohí corrects for the 143<sup>3</sup> 4 ◦ azimuth permitting, within the errors, a winter solstice alignment for this church, devoted to Saint John the Evangelist whose feast ranks close to the winter solstice, precisely. This was a rare phenomenon in the Iberian Peninsula in those distant epochs.

Another interesting consequence is that these churches seemed to comply with the norm found in the Serrablo valley, as explained early on. This could be due to the difficulty in building and properly orienting the churches in these alpine valleys with very close and abrupt horizons. However, the fact that both groups were close but not in direct contact (c. 90 km of rough land straddle them) poses an interesting problem and opens the possibility that for both groups the persistence of such orientation, slightly south of due east, may point to intentionality (perhaps similar dates for sunrise along the year).

Despite being part of different feudal territories (Counties of Aragon and Ribagorza, respectively) both were at the time dependent on the Frank kings and perhaps, given the difference with the orientation found in the contemporary churches of other parts of the Iberian Peninsula, the link should perhaps be sought for at the other side of the Pyrenees. This is something for further exploration in future research.

#### **4. The Canarian Paradigm**

Cultural astronomy studies, including both ethno- and archaeoastronomy, have now a tradition of a quarter century in the Canary Islands. The statistical relevance of astronomical implications for a certain number of sites and the spectacular character of some of the findings clearly points out to intentionality in the astronomical relationships discovered so far. There are two paradigms where this relationship is, besides, clearly related to sustainability issues: The mountain of Tindaya, in the island of Fuerteventura, and the 'Risco Caído and the sacred mountains of Gran Canaria Cultural Landscape'.

One of the earliest substantial discoveries in the islands was the probable astronomical connection of the aboriginal footprint engravings (usually called podomorphs) of Montaña Tindaya, a singular mountain dominating the northern plains of the semi-desert island of Fuerteventura (see Figure 6). Tindaya was a local reference of certain importance for ethnographic studies and also an important archaeological site where the largest sample of podomorphs in the world could be found. The mountain was also the centre of a series of aboriginal archaeological sites with obvious religious implications (Figure 6).

However, all these important issues were not enough to save the mountain from wild modern building speculation. Tindaya actually is the nucleus of an eroded volcanic cone formed by an appealing and beautiful stone called trachyte. Hence, a series of quarries were open in the skirts of the mountain, which could, eventually, have destroyed it completely (see e.g., Figure 1). In the mid 1990s, a team led by the archaeologist María Antonia Perera decided to include Tindaya and its podomorphs in a project where cultural astronomy would play the most relevant role to revalue the mountain and its environment. Despite some misfortune initiatives which tried to make a putative use of the results, such as the bizarre idea of making an 'insculpture' inside the mountain, the project was certainly successful [40].

The data showed that these petroglyphs, counted by hundreds, do not follow a random pattern but rather they have a clear custom of orientation with a concentration in the W-SW sector of the horizon (see Figure 7). Different hypotheses have been offered for this pattern and the visibility of the Peak of Teide in the distant island of Tenerife is perhaps among the most suggestive (see Figure 8). Teide, a huge volcanic cone 3714 m high, has been interpreted as a sort of axis mundi for the aboriginal populations of the Canary Islands because it is visible from all of them and it should have been really impressive either at daylight when covered by snows or at night when in an eruptive process. However, it cannot explain the whole sample alone.

**Figure 6.** Montaña Tindaya, in Fuerteventura, as seen from the ancient 'esequen' (stone circle) of Llano del Esquinzo. The southern (right) peak is virtually full of footprint engravings (podomorphs) with a non-random orientation pattern. Researchers are seated in cyclopean chairs facing the mountain. © J.A. Belmonte.

**Figure 7.** Orientation diagram of the podomorphs of Tindaya (see inset of a pair of footprint engraving), showing several topographical and astronomical references, including the winter solstice sunset (SI) and southern moon standstills (PM for Major Standstill and Pm for Minor Standstill). © M.A. Perera, J.A. Belmonte and C. Esteban.

**Figure 8.** Teide peak in faraway Tenerife Island, the axis mundi of many populations of the archipelago, as seen from Tindaya in Fuerteventura. This could be a topographic reference for orienting the podomorphs. © Gianfranco Costa.

Currently, the most suggestive hypothesis of all is the one postulating a relationship with the epoch of maximum rainfall in the island in the period from late November to late December and the vision of Venus as the evening star in combination with the crescent moon closest to the winter solstice [41]. Present day peasants and goatherds in Fuerteventura and other islands have interpreted the visibility and behavior of Venus as the evening star in this period of the year as a water carrier. Hence it could have been related to fertility cults in pre-Hispanic times [42]. As a matter of fact, cultural astronomy studies, without the need to alter the terrain and only looking at the horizon and the sky, have been able to reinforce the value of Tindaya, preserving the mountain for future generations in a sustainable way.

On the other hand, the island of Gran Canaria (see Figure 9) presented the most evolved and richest pre-Hispanic culture of the Canary Archipelago. The population had, as for each of the other islands, an undoubted proto-Berber ancestry, which lasted from the turn of the era to the Castilian conquest in 1483 AD. The social structure was complex and hierarchical, similar to a proto-state. This island is characterized by the presence of sanctuaries at the top of significant mountains and on the scarps of the huge volcanic calderas of the island, which are often called 'almogaren' thanks to the early chronicles, where particular rituals took place at precise moments of the year [43].

In particular, the area of the Caldera de Tejeda (Figure 9) presents a paradigmatic example of an adaptive process to a harsh but attractive environment, offering an excellent horizon. This includes impressive natural monuments such as the Roques Bentayga and Nublo, acting as reference landmarks where land- and skyscapes could be in close contact and permanent interaction (see Figure 10). This chain of facts suggested it as the perfect location for a cultural landscape which might be defended within the framework of UNESCO and the International Astronomical Union (IAU) Astronomy and World Heritage Initiative [6] under the name: 'Risco Caído and the sacred mountains of Gran Canaria' [44]. Risco Caído was the name of one of the most representative sites used as a sort of brand.

The area of the cultural landscape is impressive, including the Tejeda Basin and the Ravine of Barranco Hondo (where Risco Caído is located; see Figure 11). These are areas of the summit of Gran Canaria that have been inhabited since antiquity to the present day and where the local population had to make a huge adaptive effort to a not easy environment, applying sustainable practices before the word was even defined.

The relatively high cultural level of the ancient Canarians or 'Canarios', a name later extended to the rest of the archipelago, is clearly illustrated by the existence of irrigated land agriculture, with the stock of the products in communal granaries such as the one of El Alamo in Mesa de Acusa, in the western border of the Caldera. Indeed, a lunisolar calendar ought to be developed to control time and the productive cycle [45]. A large number of petroglyph stations, including alphabetic inscriptions, have been reported in Gran Canaria. The examples of the artificial sanctuary caves at Risco Chapín and Risco Caido (inside the cultural landscape limits, Figure 9; Figure 10) with the largest collection of pubic triangles in the world, which could be interpreted within a fertility cult, are among the most relevant.

The recently discovered light and shadow effects at Risco Caído [46] are indeed a highlight within this particular context. In Gran Canaria, dedicated fieldwork strongly suggests that most of the high-mountain sanctuaries, often located at high spots dominating a wide, and sometimes, impressive panorama, could be related with solar and lunar observations and, certainly astral cults [47] since: "the Canarians are idolatrous, worshiping the Sun, the Moon and other Planets" (Alvise de Cadamosto, 15th century AD [48]), or " ... they worshiped fire, the Sun and the Moon, and the Dog Star, when they started the year with grand feasting ... " (Tomas Arias Marín de Cubas, 1694 [49]). The cultural landscape under examination within the property area includes a good sample of these relationships.

**Figure 9.** Star depicts settlements in Gran Canaria: Ancient Canarian sites where astronomy did play a most relevant role. Four of them, including some of the most important, are within the limits of the cultural landscape 'Risco Caído and the sacred mountains of Gran Canaria' (red color). This property corresponds to the best preserved and most sustainable area of the island. © Cabildo de Gran Canaria.

**Figure 10.** A general view of the Tejeda Basin, the nucleus of the cultural landscape, as seen from the base of Roque Nublo (Figure 12). It is dominated by Roque Bentayga (centre left) and Risco Chapín to the right. This is a nearly perfect example of an interacting land- and skyscape. Tenerife, with Teide, is seen in the distance, to the left above the clouds. © Cabildo de Gran Canaria.

**Figure 11.** Barranco Hondo Ravine, the ancient sector presumably named Artevigua in the chronicles, where the sanctuary of Risco Caido is located. This is a perfect example of sustainability applied to a harsh environment. Roque Nublo is seen in the distance. © Cabildo de Gran Canaria.

To handle with the initiative and defend the importance of the property in front of UNESCO evaluating panels (notably the International Council of Monuments and Sites, ICOMOS), a multidisciplinary international team of specialists was created, including archaeologists, anthropologists, botanists, architects, geologists, environmental experts, developing managers and, indeed, cultural astronomers (see Figure 12). Within this framework, 'Risco Caído and the sacred mountains of Gran Canaria' initiative has been considered as an excellent laboratory where the close relationship between land- and skyscapes in human culture can be illustrated. The idea is to prove that the area selected within the island (Figure 8) is a paradigm as a marvelous example of a cultural landscape worth being declared as a World Heritage Site. In this line of argument, the following outstanding universal value (or OUV in UNESCO jargon) criteria have been settled in the proposal (Astronomically relevant issues are highlighted in bold face):

Criterion (iii): "The ensemble of archaeological sites constitutes a unique and exceptional testimony to an extinct island culture that evolved in isolation for a period of more than one thousand five hundred years. Archaeological evidence and documentary sources relative to the proposed property bear witness to the fact that this culture dates back to the first settlers that arrived to these shores from the Berber Maghreb, which in itself is outstanding, as this thus constitutes a unique case of an island culture with roots in the pre-Islamic Amazigh world, manifestations of which are few and far between. The place expresses a very strong and very original relationship of human beings with nature (both Earth and Sky). **The proposed property constitutes an outstanding testimony to an island culture that integrates the skyscape as a fundamental part of its worldview, its rituals and beliefs, and which has also developed its own astronomical culture in close harmony with the natural environment and the surrounding landscape.** Clear evidence of this is the astronomical sanctuaries, such as Risco Caído that represent the pinnacle of the evolution of this knowledge and practices. This legacy illustrates the odyssey of the indigenous island cultures of the planet that have evolved over long periods without outside influence, ultimately creating their own cosmology and a unique world of knowledge and beliefs". And:

Criterion (v): "The indigenous troglodyte settlements of Caldera de Tejeda and the surrounding area constitute an inimitable example of this type of human habitat in ancient island cultures, illustrating a level of organization of space and adaptive management of resources that is highly efficient and complex. The extensive geological backdrop and the natural landscapes fuse with the cave settlements, sanctuaries, sites and terraces, developing a unique culture that still maintains its

principal references, as well as its symbolic and cosmological connotations. This type of human settlement has survived through history, creating new ways of occupying the space that express the syncretism between the indigenous culture and the new culture established after the Spanish conquest. The survival of techniques and ancestral land uses, such as transhumance, should also be added to this. **The orientation and alignment of certain sanctuaries and artificial caves also indicate the intimate relationship that this type of settlement has with the skyscape and the principal symbolic elements of the landscape**. Spatial distribution of the settlements and the archaeological finds give us an in-depth understanding of how indigenous people used the territory of the sacred mountains. The areas surrounding the sites contain habitats and species of flora and fauna that also inform us on the way of life of the early settlers. Knowledge of the skills and cultural traditions of the indigenous settlers on the island has been definitively changed as a direct consequence of the new evidence provided by this incomparable territory".

Hence in Gran Canaria, and notably in the area of the property, a paradigmatic example of the interaction between topography and the sky is found; a paradigm which cultural astronomy has helped to disentangle. The comparative analysis made for the memory [50] suggests that there is no other site in the world where such a combination is so clearly illustrated although parallelisms could be found with Rapa Nui or Thebes in Egypt, but not in such a gigantic and outstanding scale as here.

Hence aspects like relations between astral divinities, seasonal cycles, the need to measure time or fertility worship with its rock-art symbols, is highlighted in the different pieces of evidence that illustrate the cosmology held by the ancient inhabitants of the Canary Islands.

Although it is true that an intrinsic relationship cannot be proven entirely, the evidence is suggestive and talks about a people who were able to adapt to a harsh environment that we researchers are obliged to keep today. In any event, it is not a question of interpreting an entire cultural context in accordance with the sky, just as it would be a serious mistake to forget about it.

**Figure 12.** Part of the team of scholars supporting the initiative of a UNESCO cultural landscape in Gran Canaria summit in front of Roque Nublo. The group is formed by archaeologists, anthropologists, botanists, architects, geologists, environmental experts and, indeed, cultural astronomers. © Cabildo de Gran Canaria.
