Meru yantra

Mount Meru (Sanskrit: मेरु) (also called Sumeru i.e the "great Meru") is a sacred mountain in Hindu, Buddhist cosmology, and Jain mythology considered to be the center of all physical and spiritual universes.
The Iranians claim that the Aryans came from Mount Hara. Har is another name of Shiva, who has His abode in this mountain. Some beliefs, local to that area of the Himalayas, associate mythical Mount Meru with a mountain called Kailasa near the Lake Manasarovar in Tibet,which can be traced to some later layers of Mahabharata.
For the equivalent central mountain in Buddhist cosmology, see Sumeru.
The Meru Chakra or Sri Chakra is a three-dimensional Shri Yantra, the embodiment of Sri Lakshmi (abundance) and Tripura Sundari (beauty). It is the yantra of Sri Vidya, sacred knowledge of the Goddess. It can also be seen as the unification of Masculine Divine and Feminine Divine: Shiva and Shakti, Lakshmi and Narayana, Purusha and Prakriti.
The Shri Yantra consists of triangles arranged in five levels around the center. The Meru Chakra has these same levels arranged in different heights, with the centermost level the highest. The Meru is the three dimensions of the Sri Chakra. If we returned to the two dimension Sri Chakra, and imagine that the bindu in its center is the peak of a mountain. The imagine that the mountain is built up in tiers, each tier being one of the circles of triangles or lotus petals, with the outermost square representing ground level. Now, imagine a vertical spine down the center of the mountain, then at each point that the spine and a tier intersect, there is a chakra. The peak represents Mount Meru, abode of the Gods.

The Basics of Sri Yantra:
Before starting the worship it is advisable to know about the way the Sri Yantra is constructed, what all it represents, about the 9 Avaranas, the deities, their gunas and significance, so that your worship is more meaningful. The following are the authentic details as given in various Tantra & Mantra scriptures.
Five downward pointing triangles representing Devi intersect with four upward pointing triangles representing Siva, forming 43 triangles including the central triangle.
From the five Shakti triangles comes creation and from the four Shiva triangles comes the dissolution. The union of five Shaktis and four Fires causes the chakra of creation to evolve.
At the centre of the bindu of the Shri Yantra is Kamakala, which has three bindus. One is red, one is white and one is mixed. The red bindu is Kurukulla the Female form, the white bindu is Varahi the Male form, and the mixed bindu is the union of Shiva & Shakti - the individual as the potential Shri Cakra. Varahi, the father-form, gives four dhatus to the child and Kurukulla, the mother-form, gives five dhatus to the child. Theses represent the nine dhatus of the human body.
Varahi’s four fires are the 12 (4 x 3) sun Kalas, the 12 Zodiac constellations. Kurukulla’s five triangles are the 15 (5 x 3) Kalas of the moon, 15 lunar Tithis. These nine triangles also represent the nine stages of growth of the human child in the womb.
Surrounding the 43 triangles formed by the intersection of the nine triangles is the 16 petals circle. Surrounding the 16 petal circle is an 8 petal circle. After that the 3 lines and at the outermost part of the Sriyantra there are 3 lines called the Bhupura. The 43 triangles constitute the six inner sections called Avaranas, the two circles of petals are two more avaranas and the Bhupura of 3 lines is the last Avarana.
These 9 Avaranas of the Sri Yantra have various presiding Devis. They are the Devi’s Parivar (retinue) of total 108. In the Srichakra pooja they are systematically worshipped one by one with their names and mantras. The presiding Deity of Srichakra, Devi, is Known as Lalita Tripura Sundari. The form of Devi Kamakshi of Kancheepuram is the closest resemblance of the Devi as described in the scriptures.
As the Supreme Will, Shakti is described as Consciousness-Bliss. The Saundarya Lahiri describes the universe in its subtle and gross forms as the trans- formation of Shakti. Though undergoing actual trans- formation into all these elements in their gross macro-cosmic aspect as the universe and in their subtle micro-cosmic aspect as the six chakras in the body, Shakti is not lost in the effects - she retains her identity as the Supreme Will or Consciousness-Bliss.