Classic Maya cosmology pictured the universe as a layered structure, an underworld of water and darkness below, a middle world where humans lived above it, and a stacked series of heavens further above still, and the wacah chan, the raised or standing sky, gave that structure a physical form: a great tree, generally identified with the ceiba, whose real-world height and buttress roots made it a natural candidate for cosmic symbolism among the lowland Maya, who regarded actual ceiba trees as sacred and often left them standing at the center of settlements. Maya texts and iconography describe not one but four world trees positioned at the cardinal directions, each associated with a color and a direction, plus a fifth, central tree that served as the primary axis linking the cosmic layers.
This central tree's roots reached down into Xibalba, the watery underworld, its trunk passed through the middle world of ordinary life, and its branches rose into the layered heavens, making it the conceptual channel through which communication, and in ritual contexts spirits, ancestors and deities, could move between the different registers of the Maya cosmos. Rulers positioning themselves symbolically at this axis, as Pakal's sarcophagus imagery does explicitly, claimed a uniquely privileged position at the center of the cosmic order itself.