Yantra

A yantra is meditational device used in Hindu and Tibetan Tantric meditation. From the root “yam,” meaning “to sustain,” the Yantra is a symbolic image used to maintain a focused state during meditation. A yantra is usually composed of an outer geometrical form enclosing an interior geometrical designs. Each particular design is used for a specific purpose or intent. Some of the basic elements of a Yantra are: The Bindu, or infinite point:
  Upward and downward facing triangles, symbolizing a female, watery energy, and male, fiery cosmic energy:
  A hexagram or six pointed star (shatkona), symbolizing the union of Shiva and Shakti, masculine and feminine energy: The lotus, a symbol of purity and spiritual “unfolding” (Lotus symbolism in the East is equivalent to the Western Rose in many respects): The most recognizable yantra is the Sri (abundant) Yantra. The Sri Yantra is very ancient, and is a variation on the shatkona, with nine interlaced triangles. (four female, downward facing; five male, upward facing):