The mandala (literally 'circle') is a fascinating concept, as well as often making for quite a beautiful artistic creation in itself. In a sense you might think of a mandala as being like a three-dimensional picture. What on the surface appears as a plain two-dimensional design, with the right visual approach, emerges as a three-dimensional picture. Mandalas can be in the form of paintings, patterns of sand, three-dimensional models or even whole monasteries, as in the case of Samye.

In the case of the two-dimensional mandala the correct visual approach is achieved only through meditation. The mandala is associated with Tantric Buddhism and is chiefly used in a ritual known as sadhana, or 'means for attainment'. According to this ritual, the adept meditates on, invokes and identifies with a specific deity, before dissolving into emptiness and re-emerging as the deity itself. The process, in so far as it uses the mandala as an aid, involves a remarkable feat of imaginative concentration.

A typical mandala will figure a central deity surrounded by four or eight other deities who are aspects of the central figure. These surrounding deities are often accompanied by a consort. There may be several circles of these deities, totalling several hundred deities in all. These deities and all other elements of the mandala have to be visualised as the three- dimensional world of the central deity and even as a representation of the universe. One ritual calls for the adept to visualise 722 deities with sufficient clarity to be able to see the 'whites of their eyes' and hold this visualisation for four hours.

The ultimate aim of mandala visualisation, however, is to enter the three-dimensional world of the mandala and to merge with the deity at the center of that world.