The four cardinal directions help create the axis of a Hindu temple, around which is formed a perfect square in the space available. The circle of mandala circumscribes the square. The square is considered divine for its perfection and as a symbolic product of knowledge and human thought, while circle is considered earthly, human and observed in everyday life(moon, son, horizon, water drop, rainbow). Each supports the other. The structure. In ceremonial temple superstructures, this is an 81 sub-square grid. The squares are called " padas". The square is symbolic and has Vedic origins from fire altar, Agni. The alignment along cardinal direction, similarly is an extension of Vedic rituals of three fires. This symbolism is also found among Greek and other ancient civilizations, through the gnomon. In hindu temple manuals, design plans are described with 1,4,9, 15, 25, 36, 49, 81 upto 1024 squares; 1 pada is considered the simplest plan, as a seat for a hermit or devotee to sit and meditate on, do yoga, or make offerings with vedic fire in front. The second designs of 4 meditative on, do yoga, or make offerings with Vedic fire in front. The second design of 4 padas has a symbolic central core at the diagonal intersection, and is also a meditative layout. The 9 pada desing has a sacred surrounded center, and is the 9 through 49 pada series, but 64 is considered the most sacred geometric grid in Hindu temples. It is also called manduka, bhekapada or ajira in various ancient Sanskrit texts. Each pada is conceptually assigned to a symbolic element, sometimes in the form of a deity or to a spirit or apasara. The central squares(s) of the 64 is dedicated to the Brahman (not to be confused with Brahmin), and are called Brahma padas. In a Hindu temple's structure of symmetry and concentric square, each concentric layer has significance. The outermost layer, Paisachika padas, signify aspects of Asuras and evil; the next liner concentric layer is Manusha padas signifying human life; while Devika padas signify aspects of Devas and good. The manushka padas typically houses the ambulatory. The devotees, as they walk around in clockwise fashion through this ambulatory to complete Parikrama (or Pradakshina,) walk between good on inner side and evil on the outer side. In smaller temples, the paisachika pada is not part of the temple superstructure, but may be the boundary of the temple or just symbolically represented.