This wonderful volume on lowland Maya architectural orientations complements similar studies published over the past two decades on astronomical alignments in the civic and ceremonial architecture of the Gulf Coast, Oaxaca, and central Mexico. These studies, all involving Ivan Šprajc as either lead author or coauthor, represent a systematic investigation of site orientations in Mesoamerica. When they are considered together, a pattern emerges featuring alignments to sunrise positions on the solstices and sunrise dates marking a period of 260 days (or an approximation thereof) bracketing the agricultural season (February through October). This suggests a horizon calendar that works well with the 260-day divination calendar shared throughout Mesoamerica. Actual alignments to the equinox are very rare, and those close to the equinoxes coordinate with the quarter days, marking halfway points between the solstices. Alignments also register subdivisions into 13-day and 20-day intervals, periods that are important in the divination calendar.
The introduction lists 87 sites in the Maya lowlands that are covered in the book and sources of data used for each site. Chapter 2 details the methodology employed, including a discussion of error factors and why the researchers made measurements using sight lines on east-west and north-south trajectories along the building walls instead of choosing sight lines taken from the structure's principal access point. They also note that ball courts were excluded from the study because they are usually surrounded by higher structures, making measurement of the alignments to horizon positions more problematic. The authors emphasize that their statistical analysis results in a greater methodological rigor than is commonly seen in studies published by other researchers. This certainly is the most comprehensive study of Maya orientations, but their method of statistical analysis emphasizes measurement of the building walls, rather than building to building alignments and sight lines within the buildings from windows and doors, the kinds of measurements often employed by other researchers.
Chapter 3 expands the analysis with tables and graphs recording measurements and error factors. Table 1 is most useful, listing the entire set of 271 structures, the dates they were constructed, measurements for azimuth and declination, estimated error factors, and the solar dates implied by the alignments. The remaining tables group these structures in sets that show similar alignments, with sets that also relate to the extreme horizon positions of the moon and Venus (Tables 3–5). Table 2 groups together 16 solstice alignments, including Yaxnohcah Group F, a middle Preclassic construction. Histograms and graphs enhance chapter 3, although many lack adequate explanations of the x-axis. (For this data see a 2016 article coauthored by Šprajc in Journal of Archaeological Science: Reports 9:191–202.) The remaining text in this chapter studies groups of similar alignments, noting that the largest group (Group 1) has alignments to sunrise dates in early February and late October, marking a 260-day period. There is also a separate discussion of E-Group alignments, first measured at Uaxactun in astronomical orientations to the equinoxes and solstices that involve multiple buildings. Here the authors disagree with findings published in this journal (Aveni et al., Latin American Antiquity 14:159–78), noting that the astronomical function for E-Groups is no greater than other buildings they measured, although they point out that they did not measure sight lines from the western pyramid to structures on the eastern range, relying instead on the axial orientations of individual buildings (p. 85).
Chapter 4 focuses on interpreting various groups of solar alignments and relates these alignments to ethnographic data on the agricultural cycle and Catholic saints’ days. This chapter also considers the symbolic aspects of alignments to horizon extremes for Venus and the moon, and provides an analysis of the technical aspects of observation. Venus alignments have been widely discussed in the literature, but here there is an emphasis on horizon positions of the evening star related to the agricultural cycle. The lunar alignments of a number of Maya structures are also noteworthy. In the past, only a few structures had been studied in terms of lunar orientations, so the addition of new data is most welcome.
Chapter 5 describes structures measured at specific lowland Maya sites, discussing some sites in greater detail than others. (Chichén Itzá and Tikal are covered most thoroughly.) Here it becomes evident that some questions can be raised. At Chichén Itzá, the photo taken along the north wall of the Castillo is said to demonstrate an alignment to sunset on May 20, seeming to invalidate the alignment to the solar zenith sunset (May 25 and July 20) described in my own studies, but a more detailed article by these two authors (Estudios de Cultura Maya 41:31–60) shows an alignment from inside the west doorway that marks the dates May 23 and July 21, or close to the zenith dates (which vary by a day year to year). This also demonstrates that the north wall is not at exactly the same angle as the doorway. One wonders if this could also be the case in other structures. A sunset picture on May 7 taken from inside the west doorway of the Upper Temple of the Jaguars reinforces the date derived from measurements of the north wall (17.518o azimuth, Table 1), but Figure 22 shows the sun is well above the horizon, positioned over a tree line that surely was not there in earlier times. I also had this problem, resulting in a misleading photograph of the same view in my 1988 publications, cited here by the authors, but they fail to note that I subsequently corrected my interpretation of this structure in 1999 (Star Gods of the Maya, p. 68). Other oversights are seen in the section on Yaxnohcah, where there is only a very brief mention of the Group F solstice alignment listed in Table 2, and it is not clear which structures were measured in that group. A map obtained from another source suggests that the solstice alignment would have to run along the front face of a platform that supports the entire Fidelia group. The principal pyramid (F-1) and stairways face south, but the summit of F-1 can possibly be said to have a solstice alignment, for it runs parallel to the base platform.
The final chapter concludes with discussion of interesting comparative patterns throughout Mesoamerica, noting that east-west alignments are most important and the orientation marking a 260-day interval apparently originated in the Maya area rather than at Teotihuacan. Stellar alignments to Fomalhaut are discussed further (returning to a brief treatment in chapter 3, pp. 67–68), and the authors note that this pattern is found in the Usumacinta and the northeast coast of Yucatan but not in Petén. They point out that regional patterns of orientations within the Maya area provide a possible key to cultural links.
As a reviewer, it is my job to assess the volume as a whole, including flaws, but any discussion of shortcomings should not diminish the importance of this volume in the field of archaeoastronomy (a.k.a. cultural astronomy). Not only is it the most comprehensive study of alignments in the Maya area, it also represents a great accomplishment involving many years of fieldwork to ground truth what is often not evident in standard maps. And it is also commendable that Sánchez and Šprajc have incorporated ethnographic data about the agricultural cycle into their analysis of the significance of their statistical study of alignments. This book is a very important contribution to our understanding of site planning and the calendrical periods embedded in architectural orientations.
