Water in several forms both reflects and focuses the northern portico of the Friday mosque in Isfahan. In the foreground, at the exact centre, is a small pool with a set of four arches (chahar taq), which mirror the four porticos which they face while echoing the structure of the domes inside them. To the north of this is a lotus shaped pool - a traditional Persian design which signifies life. At the rear, just in front of the portico is a font which supplies drinking water. The ritual, cleansing function is fulfilled by the fore- ground pool; the life-enhancing qualities are symbolised by the lotus pool, while the more prosaic use to quench thirst is accomplished through the font.