Monte Albán — System IV

System IV is a temple-patio-altar complex at Monte Albán, located in the northwest corner of the Main Plaza, featuring a private courtyard, broad staircases, and associated with Stele 18, an astronomical marker verifying midday.

System IV, also known as Sistema IV, is a ceremonial complex situated in the northwest corner of Monte Albán’s Main Plaza, dating to the site’s transitional and Classic periods around 100 BCE–AD 600. As a temple-patio-altar structure within this Zapotec ceremonial center in Oaxaca, Mexico, it includes a private sunken courtyard cut off from outside view, with east-west staircases and a central altar, underscoring the site’s architectural symmetry and ritual functions. Its significance lies in serving as a boundary marker for the site, incorporating astronomical elements like Stele 18, and contributing to understandings of Zapotec spatial organization and sacred topography. [1] [3]

Location and layout

System IV is positioned in the far northwest corner of Monte Albán’s Main Plaza, which spans approximately 300 m (984 ft) by 200 m (656 ft), serving as a corner boundary to the site and part of the western row of symmetrical complexes including System M and the Danzantes structure (Building L). The layout features a temple-patio-temple arrangement with a courtyard between two buildings, enclosed by low walls to the north and south, and a central altar with stairs to the east and west at the edges of a private patio area cut off from outside view. It includes a broad impressive staircase leading to the rear temple, with underground tunnels and a sunken courtyard, relating closely to the overall processional design and adjacent features like the North Platform. [1] [3]

Architecture and construction

Constructed during Monte Albán II–III (100 BCE–AD 600), System IV exemplifies Zapotec ceremonial architecture with adobe walls, likely topped with flat wood/earthen roofs, resting atop stone foundations, and cornices featuring double scapular decorative trim common to the site. The complex includes a sunken courtyard and underground tunnels, with the rear temple accessed by a broad staircase, reflecting phased development aligned with the site’s expansion. Surfaces were finished with stucco plaster, and orientations emphasize privacy and ritual seclusion, without evidence of major later modifications. [1] [3]

Sculpture and epigraphy

System IV is associated with Stele 18, the oldest and tallest monument at the site (5.8 m / 19 ft high), carved with incisions that may relate to a calendar, featuring two glyphs on the eastern side including a water sign. Interpreted as an astronomical instrument for verifying midday—one of the four Pre-Hispanic divisions of the day—Stele 18’s iconography reflects Zapotec calendrical and ritual themes, with no additional sculptures or epigraphy directly tied to the complex documented. [1] [4]

Archaeological research

Excavated as part of Alfonso Caso’s 1931–1953 Monte Albán Project using stratigraphic and ceramic analysis, System IV was documented for its symmetrical design and boundary role. In 2008, CyArk, Leica-Geosystems, and SYSTOP conducted digital recording, selecting System IV for preservation due to its exemplary features like the sunken courtyard and tunnels, with data archived in Open Heritage 3D for education and research. Modern studies integrate geophysical surveys and 3D modeling, affirming its ceremonial function without resolving debates on exact phasing due to limited artifacts. [3] [5]

Visiting notes

Visitors can appreciate System IV from the Main Plaza’s northwest edge, ascending the broad staircase to observe the courtyard and temple outlines, following a counterclockwise path that highlights its symmetry with System M and role in site boundaries. The stele and tunnels provide context for astronomical and private ritual elements. [6]

Related MAHC WIKI entries

System M
Main Plaza
Building L
North Platform

References

Sullivan, Mary Ann. (n.d.). “Monte Albán: System IV/Edifice K and Stele 18.” Bluffton University. https://homepages.bluffton.edu/~sullivanm/mexico/oaxaca/montealban/system4.html. Detailed description and images.
UNESCO World Heritage Centre. (1987). “Historic Centre of Oaxaca and Archaeological Site of Monte Albán.” https://whc.unesco.org/en/list/415/. Official listing.
CyArk. (n.d.). “Monte Albán, Mexico.” Google Arts & Culture. https://artsandculture.google.com/story/monte-alb%C3%A1n-mexico-cyark/JgURWMxaQw-fJA?hl=en. Digital preservation details.
Marcus, Joyce, and Kent V. Flannery. (1996). Zapotec Civilization: How Urban Society Evolved in Mexico’s Oaxaca Valley. Thames & Hudson. Overview of Zapotec archaeology.
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.