The configuration of the yantra is as follows:
1. There are five triangles with the apex downwards ( representing Shakti or the Female element) superimposed over four triangles with the apex upwards ( representing Shiva or the Male element).
2. The central configuration of triangles is surrounded by an eight-petalled lotus.
3. The eight-petalled lotus is surrounded by a sixteen-petalled lotus.
4. Next come the triple rings.
5. Last of all is the outer square with four portals.
This is the basic structure, but this whole chakra consists of Nine Enclosures, each representing a step in the journey inwards to the sanctum of Lalita, a step in our onward spiritual progress. They are:

1. "Trailokyamohana Chakra" ( Enchanter of the Triple World)-( see picture below)

The region between the four sides of the square and the three concentric circles is the first enclosure.
This is the most external and world-oriented of the nine enclosures and is the first 'enclosure' one crosses on the path to self-realization to overcome the material aspect in oneself.

2. " Sarvasaparipuraka chakra" ( Fulfiller of all Desires)-

The second enclosure comprising sixteen petals lies just within the three concentric circles. The 16 petals represent the 16 Yoginis (female yogic power or attendant deity) associated with the attainment of desires by the cultivation or strengthening of power over the following ( starting from the east in an anti-clockwise manner)-
Desire, Intellect, Ego, Sound, Touch, Form, Taste, Smell, Thoughts, Fortitude, Recollections, Verbal Labels, Sources of Phenomena, Selfhood, Immortality and Body.
This is the next step in self-realization- power over these aspects within ourselves.
The corresponding centre in the human body is the Muladhara or Root chakra.

3. "Sarvasankshobhana chakra" ( The Agitator of All)-

The third enclosure is the one with the eight-petalled lotus. The eight petals represent the eight forces which are psychophysical in nature (starting from the east)-
Speech, Apprehensions and reception, Locomotion, Urges of the body and elimination, Pleasure, Reactions, Concentration and Detachment.
Control over these forces is the next step on the path to self-realization.
The navel region in the human body is associated with this enclosure and represents absorption of all forces of 'agitation'.

4. "Sarva-saubhagyadayaka chakra" ( The Giver of All Auspiciousness)-

This fourth enclosure is the fourteen cornered figure created by the intersecting triangles. They stand for the fourteen realms, and also represent the fourteen main vital channels in the human body ( the 'nadis').The clearing and activating of these channels creates the space needed to bring in auspiciousness and prosperity- one more step in the path to self-realization.
The corresponding centre in the human body is the Anahata or Heart chakra.

5. "Sarvartha Sadhaka chakra" ( The Accomplisher of All Purposes)- ( see picture below)

The ten-cornered figure immediately inside the fourteen-cornered one is the fifth enclosure. The ten corners house the ten auspicious deities who bestow all good things like- fulfilment of desire, overcoming of obstacles, removing of suffering, beauty of body, prosperity, etc.
Clearing of the channels in the previous enclosure creates the space and 'invites' these deities to bestow these good things.
The corresponding centre in the human body is the Vishuddha chakra or Throat chakra.

6. "Sarva rakshakara chakra" ( The Protector of All)- ( see picture below)

The sixth enclosure is the inner ten-cornered one inside the previous one. The ten corners represent the ten powers of vital fire associated with digestion and elimination. It has the nature of fire, and activates the refinement and purification of bodily desires and actions, protecting us from 'dis-ease' in the refined sense.
This is the next step in 'purifying' ourselves towards self-realization.
The Manipura or Solar Plexus is the corresponding centre in the human body.

7. "Sarvarogahara chakra" ( The Remover of All Diseases)-

The eight-cornered figure within the smaller ten-cornered figure is the seventh enclosure. It represents the powers responsible for the eight fundamental urges-
Cold, Heat, Happiness, Desire, Pain, Activity, Inertia and Wisdom.
All dis-ease in the body is associated with one or another of these urges. Positive expression is the way to overcome dis-ease. This chakra helps in activating positive expression, which is the next step in the 'refinement' of the self on the path to realization.
The corresponding centre in the human body is the Svadhishtana chakra ( below the navel).

8. "Sarvasiddhiprada chakra" ( The Giver of All Accomplishments)-

This is the primary triangle situated in the centre of the yantra with the apex pointing downwards. The three corners of the triangle represent three forms of the power of the mother- Goddess:
            Kameshwari ( symbolizing the Moon)
            Vajreshwari ( symbolizing the Sun)
            Bhagamalini ( symbolizing Fire)
The three units also symbolize the three fundamental tendencies of existence-
Desire ( 'Iccha'), Knowledge ( 'Jnana'), and Activity ( 'Kriya').
Reaching this point in self-realization brings us very close to bliss. This chakra brings power over these three tendencies.
The Ajna or Third eye chakra is the corresponding centre in the human body.

9. "Sarvanandamaya chakra" ( Full of All Bliss)-

Although called an enclosure it is actually the point or 'bindu' in the centre of the primary triangle. It is composed of three dots or three elements from the primary triangle-
Moon (red), Sun (white), and Fire (mixed colour).
It is here that one is completely united with the Divine ( Goddess Lalita) and there is freedom from duality. This is the ultimate in self-realization.
The Sahasrara or Crown chakra is the corresponding centre in the human body.

Here are paintings from this series of the Nine Enclosures, as well as more representations of the Sri Yantra (all nine enclosures are available as prints, and a few as original works on canvas):