Ancient Rome was built nearly 2,000 years ago, but some might say that it didn't reach its apotheosis until much, much later. The perfection of the imperial city was all very well, this argument would run, but it wasn't until centuries of weather and plunder had turned it into a vast, tree-snarled ruin, a stage on which Reason and Nature were locked in silent combat, that the place came into its own. And where would the speaker have got these ideas? Almost certainly from the work of Giovanni Battista Piranesi, whose Vedute di Roma, a series of 135 etchings made between 1748 and his death 30 years later, are the ultimate expression of Romantic decay. Piranesi wasn't the first or the only artist to support himself by etching the sights (vedute, literally "views", were the postcards of the 18th century), but in his perseverance he turned a minor art into a major one. Whereas the veduta journeymen produced dutifully accurate scenes with all the atmosphere of architectural models, Piranesi's have a dark and unforgettable presence. Temple, villa and victory arch don't take their place in bland vistas, but loom disconcertingly like immense stone ghosts. Aware of the soul of buildings as well as their proportions, Piranesi can make a black window in a white wall seem on the verge of disclosing some final, wind-hardened truth. Above all, every etched line, whether describing column, creeper or goat, is animated by the same dancing force. With a technique closer to that of painter than topographer, Piranesi doesn't record facts, but creates a world.
It was with the Vedute that Piranesi made his living and his name, creating such a potent iconography of ruin that those schooled on his plates, among them Goethe, tended to be underwhelmed by Rome itself. By contrast, the series known as the Carceri (Prisons), on display at the British Museum for the next six months, were first published anonymously and at a knock-down price. But it is with this comparatively small-scale project, a mere 16 images of shadowy, cavernous, nightmarish dungeons, that Piranesi has made most impact on the modern world.
One of the first people to write about them was Thomas De Quincey in The Confessions of an English Opium-eater (1822), comparing the endless ascension of staircases and balconies to the dream-architecture of his narcotics haze. Some years later, the French Romantic poets became obsessed with their gloomy majesty, Theophile Gautier going so far as to plan a production of Hamlet with a Carceri-like set. Closer to our own time, both M C Escher's multi-gravitational buildings and the technocratic cities in films like Fritz Lang's Metropolis are greatly indebted to the Carceri, not to mention the endlessly unfolding spaces of virtual reality. If the Vedute concern themselves with the long perspective of time past, the Carceri seem to evoke the more sinister perspectives of the future and the mind.
What links the two series is Piranesi's brilliant manipulation of scale. The views of Rome juxtaposed the broken vastness of the ruins with the woodsheds and hovels that have grown up around them, the contrast implying a fairly spectacular fall from grace on the part of mankind. The Carceri do something similar, although in this case Piranesi pits tiny figures against columns and arches so immense that they hardly seem the product of human labour at all. This colossal penitentiary is the real subject here, the figures only serving to punctuate its endless sprawl into unseen, echoing heights. But are they there in body or merely in spirit? Piranesi's etching technique, a looser, sketchier line that forsakes the daylight clarities of the Vedute for a strange atmosphere of dream or memory, would suggest the latter. The needle has become an instrument of suggestion rather than precision, walkways and walls seeming to take form and dissolve again in front of your very eyes.
And yet, for all their wonderful solemnity, I still find it hard to look at the Carceri without thinking of Nintendo. All those stairways, ramps, bridges and balconies, that endless play of architectural forms through a peculiarly unreal space, inevitably suggest, for someone brought up in the late 20th century, the nervous onward movement of some pixellated imp. Start thinking like this and the similarities multiply - those sinister groupings of torture equipment come to seem like pitfalls to be avoided, that stairway of precariously floating blocks suddenly recalls an almost identical one in SuperMarioLand. But isn't all this incredibly petty-minded? Isn't seeing the Carceri as precursors of the Gameboy to trivialise them utterly? Maybe not, when you recall the feeling they give of utter entrapment, utter subjugation, and when you then remember the role that computer systems play in the modern state. And when you consider that the computer game is merely that sinister power's smiling, childlike face.
Piranesi's Carceri (Prisons) are at the British Museum (020 7323 8000) until 21 April 2003
