Inside, past flashy office blocks, corny pedestrian piazzas, beggars and drunks, the cathedral hides a cavernous interior that reduces nearly everyone who comes here to silence, and many to prayer. Here, banks of candles flame and gutter in dark chapels, their uncertain light reflected from polychrome marble panels, cool to the touch on summer days. They shine, too, on ceilings that, if you do not come too close, might be from Ravenna, Torcello or Byzantium itself.
The upper reaches of the nave disappear into Stygian darkness on dull days, their ineffable gloom explored only by tiny halogen bulbs burning from the fronds of immense chandeliers laced with metal rosary beads. Heavenly shafts of daylight pore down from Roman windows set vertiginously above the sanctuary and touch the suffering face of a painted crucified Christ. The light is so strong in this chiaroscuro space, where time is a perpetual gloaming, that it seems electric.
Here is a place that humbles the haughtiest. Here is a church where snobbery has no home and class divisions are anathema. Like all great churches everywhere, it is also a home for anyone seeking quiet or contemplation, not just Catholics, but people of every creed, and those with none at all. Here is proof that the architectural setting of worship matters. Of course, one can pray anywhere, at any time, but the experience of this numinous interior puts one in a frame of mind conducive to contemplation.
Here, too, is an interior so vast that one can slip into a service without comment, feel part of a greater whole without losing one's individuality and, indeed, withdraw from the hurly-burly of burger-fuelled, superstore- satiated life beyond.
It boasts Stations of the Cross by Eric Gill. It is also a truly divine setting for Monteverdi's Vespers (played here in candlelight every year). And - though Ruskin would turn his nose up here, and puritans hold them - the cathedral smells wonderfully of flowers, incense, candlewax, brick and polish. It is, as Kenneth Powell explains on this page, a masterpiece.