The mandala, formerly reserved only for insiders, and now so widely known. Mandalas are Buddhist art work that promotes concentration at a point not only for those who practice but also for those who do meditation. Mandala is a Sanskrit term meaning "universe". This was originally found in ancient cultures such as India, particularly in the tradition of Buddha.

You can find mandalas as three-dimensional structures carved out of wood or painted on canvas or walls as meditational focus point. The sand mandalas are both intricate and difficult to create but they are best known for their most striking appearance and representing the ephemeral and the timeless good quality. Sand mandalas destroyed in the end to show the impermanence of all phenomena.

The Mandala in Tibetan Buddhism

Buddha Shakyamuni first taught a fundamental vehicle (now found in some aspects of the Pali Theravada tradition), then a Universal Vehicle (or Mahayana, practiced today in some countries like Vietnam, China or Japan) and finally a Tantric vehicle, which offers a many ways to rapidly progress towards enlightenment.
This vehicle called Vajrayana is widely accepted as coming from the Buddha himself and was transmitted through centuries from India to other countries like Korea, Japan and eventually to Tibet. Tibetans were able to maintain and study the entire teachings of the Buddha and to give it a very complete meaning and form that has come to be known as Tibetan Buddhism. The Mandala naturally finds its place in this Buddhist tradition.

Some keys on the symbols it contains:

This is clearly awakened qualities of a particular Buddha enthroned in its center while on a lotus. The lotus seat in a palace with four gates in cardinal directions, the eastern gate is still low because the initiated disciple enters first when the sun appears in the east. In the square outside the palace are the gardens, then the rest of the "pure land" with auspicious signs, victory banner, wish fulfilling jewel etc.
Finally, there are three devices that circle the lotus petals, which represents the pure nature of this perfect universe. Although the lotus is grown in the mud, it is free od dirt and the water and other elements flourish it into an immaculate and fragrant flower. The mandala though extant among the universe is not stained by the matrix of ignorance and reveals the essential purity of the enlightenment.
The awakening is as indestructible as a diamond that is why the second concentric circle is that of vajras or adamantine scepter.
Finally, the last circle of fire extends to infinity as a mandala is without limits and materializes a primordial wisdom which removes the darkness of ignorance to attain an innate self.
As a whole universe, it is three dimensional and they can be known by the thickness of the first more pronounced patterns in the center and less present ones on the outside.

The sand mandala

There are hundreds of different mandalas depending upon which initiations are given. One example is the mandala of Amitayus which is round in shape, the mandala of Vajra Yogini which is triangle, and the mandala of Medicine Buddha is rather square etc. The shapes and colours are defined by the great masters according to the schools of Buddhism to which each teacher belongs.
In ancient times, the mandalas were constructed with precious stones such as ruby, turquoise, lapis etc. Today we use simple coloured sands.

When the mandala is completed, it is destroyed and the sand is then assembled in a vase. The base remains empty allowing the followers to return to the essential nature of very existence i.e. emptiness of all intrinsic existence.
The sands are blessed and then scattered into a river to symbolize the new beginning - part of impermanence - the causality.