The world mountain is the motif of a great mountain standing at the centre of the world, joining earth to heaven and frequently serving as the dwelling of the gods. It is a particular form of the axis mundi and one of the most architecturally productive images in the history of religion.
Mount Meru is its most developed instance. In Hindu, Buddhist and Jain cosmology Meru or Sumeru stands at the centre, surrounded by concentric rings of continents and oceans, with heavens rising above it and hells beneath; the sun, moon and planets circle it, and the human continent of Jambudvipa lies to its south. The scheme was not a description of the observed world and was recognised as such within the traditions, where it functions as a cosmological and ritual map rather than a geography. Its architectural expression is extraordinarily wide: the temple as a model of Meru is explicit in Hindu and Buddhist building, in the Khmer temple-mountains of which Angkor Wat is the greatest, in the terraced mass of Borobudur, and in the structure of the stupa and the tiered form of the pagoda.
Other traditions supply their own. Mesopotamian ziggurats have been read as artificial mountains, and their Sumerian names, one at Babylon meaning the house of the foundation of heaven and earth, support the reading. The Hebrew Bible has Zion as God's holy mountain and the mountain of the LORD's house established as chief among the mountains (Isaiah 2:2), with Sinai as the mountain of encounter. Greek religion has Olympus. Japan has Fuji and an extensive tradition of sacred mountains with their own ascetic practice in Shugendo. China has the five sacred peaks organised by direction, with Taishan foremost and imperially sacrificed upon.
Mount Kailash in western Tibet is the case where the cosmological idea and an actual mountain coincide most completely. It is identified with Meru in several traditions and is sacred simultaneously to Hindus as the abode of Shiva, to Buddhists, to Jains as the site of the first Tirthankara's liberation, and to Bon. It is circumambulated rather than climbed, and out of respect for that it has never been summited, a rare case of a religious prohibition holding firm against modern mountaineering.
The motif's persistence is not difficult to account for: mountains are the visibly highest points, are where weather begins, are difficult of access, and are where the earth most nearly reaches the sky. The comparative category is useful, and the standard caution about the axis mundi applies here as well, identifying instances is not the same as demonstrating that they mean the same thing to those who hold them.