of the plaza, respectively. The main western structure is typically terraced (i.e. has several levels), with inset stairways on each of its four sides, with only the eastern stairway, leading from the plaza, providing access to the summit. The stairways have large balustrades which protrude from the pyramid, which were decorated with large stucco masks and panels of architectural art. In other examples, believed to be of a later date, this quadripartite stairway configuration is lacking. E-group complexes are named after their prototypical example, Structure E-VII-sub at the site of Uaxactun. They were first identified as a meaningful complex by archaeologist Frans Blom in 1924, who excavated the site under the auspices of the Carnegie Institution of Washington. It has been theorized that these E-groups are observatories, because the eponymous group at Uaxactun contains alignments corresponding approximately to sunrises on the solstices and equinoxes. However, the architectural sequence documented in excavation reports reveals that these alignments connect elements from different periods and thus could have never been observationally functional. Besides, all other E-groups have different orientations, which pertain to widespread groups of astronomical alignments that are also embedded in a number of buildings of other types. Therefore, and considering that their primary uses were ritual and funerary, there are no grounds to designate E Groups as observatories. Other ideas seem to stem from the possible creation story told by the relief and artwork that adorns these structures. Triadic Groups They consist of an elevated platform (either an extensive acropolis or a steep pyramid) with a monumental stairway, with a central building facing the stairs, and two lateral structures facing each other on both sides of the platform. This formal complex has been attributed to the earthly re-creation of the Celestial Hearth (modern-day constellation of Orion), or a stage for enthronement rituals. Most recently Triadic Groups have been interpreted as sanctuaries commemorating Maize God's resurrection upon the Flowery Mountain. Such complexes appear during the Late Preclassic times and gradually decrease in number until their disappearance in the Early Postclassic. Pyramids and temples Often the most important sanctuaries sat atop towering Maya pyramids, some of over two hundred feet, such as that at El Mirador. The sanctuary on top commonly was heightened by a crest or roof comb. While recent discoveries point toward the extensive use of pyramids as tombs, the temples themselves seem to rarely, if ever, contain burials. Maya pyramids