Yantra comes from India. A Yantra is a symbolic Picture that represents a deity (which means God or Goddess). Tantra and mantra sound similar to Yantra but they are different. A Yantra is a geometric shape, Tantra is another form of yoga; yoga means union. You meditate on Yantras to open a doorway to an energy form.


 
The most celebrated YANTRA in India is the Sri YANTRA, the YANTRA of Tripura Sundari. It is a symbol of the entire cosmos that serves to remind the practitioner of the nondifference between subject and object.
 
GANESH YANTRA (WITH MOUNTING) Ganesh, the elephant-headed god, is invoked at the beginning of every undertaking in order that any obstacles may be removed and success may be achieved. Ganesh is known as the remover of obstacles from our paths. Meditation on the geometrical design or Yantra of Ganesh, inspires and assists the initiate to create balance within himself/herself. This yantra should be placed, facing the front door, or the door of your room.

 Information was found on yantras @ indiayogi.com and sivashakti.com
 September 2002