Axis Mundi is a term from comparative religion for the world axis — the point or line at the center of a cosmology where heaven, earth, and underworld meet and passage between them becomes possible.
The phrase is Latin, joining axis with mundi, "of the world." Its use as a technical term in the history of religions is generally credited to Mircea Eliade, who developed it through the 1950s as part of an argument that sacred space is not homogeneous: a culture establishes a center, and that center orients everything else.
The axis appears in a small number of recurring physical forms. Cosmic mountains hold the position in several traditions — Meru in South Asian cosmology, Haraberazaiti in Iranian tradition, Himinbjörg in Scandinavian. Cosmic trees do the same work with a different geometry, roots in the underworld and branches in the sky, as with the Norse world ash Yggdrasil. Built structures repeat the form at human scale: temples, ziggurats, stupas, pillars, the center pole of a tent. That repetition is what makes a temple a center rather than a location.
The human body carries the same structure inward. The Kabbalistic Sefirot and the Hindu and Buddhist chakra systems both map an ascending column through the body, and disciplines such as yoga and tai chi proceed from the premise of the body as the axis itself. This is where the concept meets the 📝Macrocosm and Microcosm principle — the center is reproduced at every scale rather than existing at one place.