Greening Tehran: Tehran's authorities have decided to prevent their city from spreading further up the mountain slopes, and to save the land for a recreational area for all citizens.

Since the 1950s, Tehran has exploded from half a million people to ten million, expansion fuelled by oil money. It sprawls over 600 square kilometres of the southern slopes of the Alborz mountains, and has obliterated many of the public and private gardens which gave the city a generous, verdant atmosphere. Since 1993, the city authorities have decided with much vision to limit urban expansion up the mountains, to conserve and enhance the existing natural environment, and to provide a large recreation area for citizens.

The Bagh-e-Ferdowsi is about 30 hectares in extent and rises from 1800 to 2100m above sea level. It builds on the earlier Jamshidieh Park (by the same team) and has four zones: city perimeter; family recreational facilities on the lower slopes; areas for trekking and mountaineering; and the natural wilderness of the upper slopes. The design has emerged from sympathetic interpretation of existing topography and local vegetation, with the design team often producing proposals by making sketches on transparent overlays on top of topographical photographs. Human intrusion was minimized. Materials for paths, walls and other structures were largely found within the park boundaries. Water is used extensively in cascades and pools. Drip-fed water features recall the significance of the element in traditional Persian oasis gardening, without copying forms more suitable to flat land, rather than Bagh-e-Ferdowsi's often steep slopes. Recreational pavilions are rather kitsch.

Technical assessor, Jolyon Leslie describes the park design as 'exemplary', and says the great variety of its spaces 'responds well to both the functional and psychological needs of visitors'. It enjoys, he says, 'huge popularity among the public', but though there is a heavy load of visitors, the park remains in generally good repair, and has been an example to other municipalities in Iran.