Sri yantra
Sri yantra, also known as Sri Chakra, is called the mother of all yantras because all other yantras derive from it. In its three dimensional forms Sri Yantra is said to represent Mount Meru, the cosmic mountain at the centre of the universe.
The Sree yantra shows the consciousness empowering and ultimate enlightenment. The Sri Yantra is conceived as a place of spiritual pilgrimage. It is a representation of the cosmos at the macrocosmic level and of the human body at the microcosmic level (each of the circuits corresponds to a chakra of the body).
The Sri Yantra is a configuration of nine interlocking triangles, surrounded by two circles of lotus petals with the whole encased within a gated frame, called the "earth citadel". The nine interlocking triangles centered around the bindu (the central point of the yantra) are drawn by the superimposition of five downward pointing triangles, representing Shakti ; the female principle and four upright triangles, representing Shiva ; the male principle. The nine interlocking triangles form forty three small triangles each housing a presiding deity associated with particular aspects of existence.
The universe created and sustain through the theory of sree yantra. It shows timelessness of spirituality. Actually meditation is witnessing or continuing in present without thoughts. Which means, continue without past and future. For that we should destroy our conditioning, ego or personality (AHAm). Sree yantra is a school of world spirituality of meditation.

Together the nine triangles are interlaced in such a way as to form 43 smaller triangles in a web symbolic of the entire cosmos or a womb symbolic of creation. Together they express Advaita or non-duality. This is surrounded by a lotus of eight petals, a lotus of sixteen petals, and an earth square resembling a temple with four doors. The various deities residing in the nine layers of the Sri Yantra are described in the Devi Khadgamala Mantra.

The Shri Chakra is also known as the nav chakra because it can also be seen as having nine levels. "Nine" comes from "Nau or Nava" of Sanskrit. Each level corresponds to a mudra, a yogini, and a specific form of the deity Tripura Sundari along with her mantra. These levels starting from the outside or bottom layer are:

1.       Trailokya Mohan or Bhupar, a square of three lines with four portals

2.       Sarva Aasa Paripurak, a sixteen-petal lotus

3.       Sarva Sankshobahan, an eight-petal lotus

4.       Sarva Saubhagyadayak, composed of fourteen small triangles

5.       Sara Arthasadhak, composed of ten small triangles

6.       Sarva Rakshakar, composed of ten small triangles

7.       Sarva Rogahar, composed of eight small triangles

8.       Sarva Siddhiprada, composed of 1 small triangle

9.       Sarva Anandamay, composed of a point or bindu

The Sri Chakra  is the symbol of Hindu tantra, which is based on the Hindu philosophy of Kashmir Shaivism also. The Sri Yantra is the object of devotion in Sri Vidya.

The two dimensional Sri Chakra, when it is projected into three dimensions is called a Maha Meru (Mount Meru).This concept is resemble to the energy system of Egyptian pyramids.

Thus the Supreme Reality splits itself spontaneously, as it were, into two sections - one appearing as the subject and the other as the object. The Purnahanta which is the essence of Supreme Reality disappears after this cleavage: the portion to which limited egoism attaches being the subject and the other portion free from egoism the object. The object as thus making its appearance is the Unmanifest (avyakta) Nature from which the entire Creation emanates and which is perceived by the subject as distinct from itself.

It has been observed that Chaitanya is of the nature of self-luminous Light (sphurat.h prakAsha), which may shine on itself (svatma), in which case it is known as Ahanta, or I-ness may rest on the Non-ego (anatma) and express itself as Idanta or This-ness. The essence of Chaitanya consists in the fact that the light (prakasha) is always confined to itself. This universal Ego or 'I' stands, behind all dualism. The Supreme Ego is universal, as there is nothing to limit (parichaheda) or to differentiate it, and the entire visible universe exists in identity with it. But this characteristic by its very nature is absent from Matter (jada), which is not self-manifest. Just as light and heat co-exist in fire, in the same way universal Ahanta and Freedom or Sakti co-exist in Chaitanya. This freedom is Maya which though essentially identical with Chaitanya (chidekarupa) brings out varieties of an infinite kind, but in bringing out this variety it does not in the least swerve from the Essence.

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