Sacred places constitute world centers (omphalos) with the altar or place of prayer as the axis. Altars, incense sticks, candles and torches form the axis by sending a column of smoke, and prayer, toward heaven. The architecture of sacred places often reflects this role. Every temple or palace--and by extension, every sacred city or royal residence--is a Sacred Mountain, thus becoming a Centre. The stupa of Hinduism, and later Buddhism, reflects Mount Meru. Cathedrals are laid out in the form of a cross, with the vertical bar representing the union of Earth and heaven as the horizontal bars represent union of people to one another, with the altar at the intersection. Pagoda structures in Asian temples take the form of a stairway linking Earth and heaven. A steeple in a church or a minaret in a mosque also serve as connections of Earth and heaven. Structures such as the maypole, derived from the Saxons' Irminsul, and the totem pole among indigenous peoples of the Americas also represent world axes. The calumet, or sacred pipe, represents a column of smoke (the soul) rising form a world center. A mandala creates a world center within the boundaries of its two-dimensional space analogous to that created in three-dimensional space by a shrine.