Monte Albán — Building P

Building P is a Classic period structure at Monte Albán, functioning as an astronomical observatory with zenith tubes for observing the sun’s passage, highlighting Zapotec advancements in astronomy.

Building P, also known as Edificio P, is a temple platform located on the east side of Monte Albán’s Main Plaza, dating to the site’s Classic period around AD 350–800. As an astronomical observatory within this Zapotec ceremonial center in Oaxaca, Mexico, it features observation chambers with zenith tubes for tracking the sun’s zenith passages, essential for calendrical and agricultural purposes. Its significance lies in demonstrating Zapotec astronomical knowledge, aligned with other structures like Building J, and contributing to understandings of Mesoamerican science and ritual practices. [3] [4]

Location and layout

Building P is situated on the eastern side of Monte Albán’s Main Plaza, which measures approximately 300 m (984 ft) by 200 m (656 ft), positioned centrally on the east boundary, directly opposite Building H with the Adoratorio (Sunken Patio) in between. The layout includes a temple platform with a monumental staircase facing west towards the plaza, incorporating observation chambers and zenith tubes oriented for solar observations. It relates spatially to the site’s astronomical alignments, including a 108° relationship with Building J, emphasizing its integration into the ceremonial landscape near the Ballcourt and other central structures. [1] [5]

Architecture and construction

Constructed during Monte Albán III (AD 350–800), Building P features a stone temple platform with a broad monumental staircase, topped with sets of columns and finished in stucco, reflecting Zapotec architectural styles with scapular cornices. The structure includes specialized observation chambers with vertical zenith tubes—narrow shafts allowing sunlight to pass at specific times—designed for precise astronomical measurements. Construction phases align with the site’s Classic period expansion, using local stone and adobe, without noted later modifications. Orientations are calibrated for zenith passages, occurring twice yearly at this latitude. [3] [6]

Sculpture and epigraphy

Building P lacks prominent sculpture or epigraphy, consistent with its functional role, though associated finds include a famous jade bat mask discovered in a nearby burial, potentially linked to ritual offerings. No specific glyphs or carvings are documented on the structure itself. [1] [7]

Archaeological research

Excavated by Alfonso Caso in the 1930s as part of the Monte Albán Project, Building P was studied through stratigraphic methods, with ceramics confirming its Classic dating. Anthony F. Aveni’s 1981 analysis identified zenith tubes for solar observations, linking it to Mesoamerican astronomy. Recent geophysical surveys, including ground-penetrating radar, have explored buried features, while alignments with Capella’s heliacal rising (275 BCE–AD 100) suggest early observational use. Debates on precise functions persist, but consensus affirms its astronomical role. [3] [8]

Visiting notes

Visitors can view Building P from the Main Plaza’s eastern edge, ascending the monumental staircase to observe the platform and chamber outlines, following a clockwise path that highlights its astronomical alignments with Building J. The site emphasizes its role in solar observations for understanding Zapotec calendars. [4]

Related MAHC WIKI entries

Main Plaza
Building J
Ballcourt
The Palace

References

Sullivan, Mary Ann. (n.d.). “Monte Albán: Buildings on east side of Grand Plaza.” Bluffton University. https://homepages.bluffton.edu/~sullivanm/mexico/oaxaca/montealban/eastside.html. Description of east side structures.
UNESCO World Heritage Centre. (1987). “Historic Centre of Oaxaca and Archaeological Site of Monte Albán.” https://whc.unesco.org/en/list/415/. Official listing.
Aveni, Anthony F. (1981). “The Observation of the Sun at the Time of Passage through the Zenith in Mesoamerica.” Journal for the History of Astronomy, xii, 51-70. https://adsabs.harvard.edu/full/1981JHAS…12…51A. Analysis of zenith tubes.
Roam. (2022). “The Ultimate Guide to Visit the Ruins of Monte Alban in Oaxaca.” Life on the Roam. https://lifeontheroam.com/monte-alban-oaxaca/. Visitor guide with observatory details.
Marcus, Joyce, and Kent V. Flannery. (1996). Zapotec Civilization: How Urban Society Evolved in Mexico’s Oaxaca Valley. Thames & Hudson. Overview of site structures.
Uncovered History. (2013). “Monte Alban – Ancient Observatory.” Uncovered History. https://uncoveredhistory.com/mexico/monte-alban-ancient-observatory/. Discussion of alignments.
Caso, Alfonso, Ignacio Bernal, and Jorge R. Acosta. (1967). La Cerámica de Monte Albán. Instituto Nacional de Antropología e Historia (INAH). Excavation reports.
INAH. “Monte Albán.” Lugares INAH. https://lugares.inah.gob.mx/en/node/4351. Site description.