What is a yantra?

Yantra literally means "support" and "instrument".
A YANTRA is a geometric design acting as a highly efficient tool for contemplation,
concentration and meditation.
YANTRAS carry spiritual significance : there is a specific meaning for each of them,
that leads us to higher levels of consciousness.
The YANTRA provides a focal point that is a window into the absolute.
When the mind is concentrated on a single, simple object (in this case a YANTRA),
the mental chatter ceases. Eventually, the object is dropped when the mind can remain empty
and silent without help. In the most advanced phases,
it is possible to attain union with God by the geometric visualization of a YANTRA.
The YANTRA is like a microcosmic picture of the MACROCOSM. 
The YANTRAS are often focused on a specific deity and so by tuning into the different
YANTRAS you can tap into certain deities or creative force centers in the universe.
YANTRAS are usually designed so that the eyes are carried into the center,
and very often they are symmetrical.
When one focuses on a YANTRA, his mind is atomatically "tuned in"
by RESONANCE into the specific form energy of that YANTRA.
The process of RESONANCE is then maintained and amplified.
Basically YANTRAS are secret keys for establishing RESONANCE with the benefic
energies of the MACROCOSM. Very often the YANTRAS can put us in contact with
extremely elevated energies and entities, being of invaluable help on the spiritual path.

Yantras of the 10 Cosmic Powers

Yantra of the Great Cosmic Power KALI - The Power of Time, erotic energy, continuous transformation and The Night of Eternity