Take any major historical civilization, any major human development such as the Renaissance, the Industrial Revolution, or even the present-day concerns for the environment and conservation, and examine their effect on the art of garden design at the time - and what do you see as the major focal point in the center of the resulting gardens? Water.

The city states that sprang up over 5,000 years ago in the Near East around the Tigris and the Euphrates rivers, and also, of course, around the Nile in Egypt, probably gave rise to the art and practice of horticulture as we know it, for growing food and for social amenity value. Water was naturally important in these baking hot areas for the irrigation of crops, but here the ruling classes, which were synonymous with the high priests of the current religions, had the luxury of water channeled directly into the confines of their own palace grounds for the purposes of stocking fish and plants in pools, or the watering of trees.

By the ninth century BC, with the rise of the Persian Empire, the concept of the garden had evolved into that of 'paradise' on earth. In the dry stone landscape that is now Iraq, small enclaves of civilization sprang up that were totally reliant upon a meager water supply that very often had to be channeled several kilometers from the base of a mountain.

By the Sassinid period of the Persian Empire in the third century AD, the garden had taken on a wholly symbolic form. The perfection of God's creation could only be represented symbolically, and as far as gardening was concerned, the irrigation channels remained, dividing the garden into four quarters, meeting at right angles in the center: this represented the universe that was divided into four parts. A tree, and then later a fountain in the center represented the Tree of Life.

During the fourth century BC in the equally refined Greek civilization, we find another very self-conscious type of philosophical man, reflecting on his place in the universe. He felt superior to nature, and made models of his gods in his own image as he developed the art of the sculpture.

The Greeks did very little to develop the art of gardening, although certain grottoes and holy places may have been tended as natural gardens, accessible only to an elite or a cult of the resident god or oracle. The concept of the grotto would continue through Roman times, re-emerging constantly right through to the present time.