The Kingston 'fatberg' and our morbid fascination with the underworld The dark world beneath our city streets is stranger than you'd think. Those fathomless ink-black labyrinths of dripping brick can play host to horrors that we would all prefer never to think about - as the residents of otherwise immaculate Surrey town Kingston upon Thames have discovered. In their case, it is a monster build-up of toxic fat and wet-wipes in local sewage pipes - a glistening yellow/white mass the size of a bus that wouldn't look out of place in a Quatermass horror story. The point is that Britain's urban underworld was largely built in Victorian times; and our generation might be the one that makes these miracles finally collapse. The Kingston "fatberg" - resolutely defeated by sewage worker Gordon Hailwood and his team, of whom more later - also shines a light into our murky relationship with the world below. The darkness both repels and fascinates. Not just in the case of the old sewers. Think of the mesmeric quality of underground railways; and of hidden rivers, covered over hundreds of years ago but which can still be heard - faint, swooshing echoes - at points on the surface. Think of the amusing conspiracy theories about secret subterranean networks, from Buckingham Palace to Salisbury Plain. In Liverpool, there has been the continued excavation of the Williamson Tunnels under the Edge Hill district. Built by philanthropist Joseph Williamson in the late 1800s, no one now seems to know quite what they were for: a means of providing construction employment for the destitute? A doomsday bolt-hole? This maze of brick tunnels, the arches sinisterly elegant under torchlight, is something that touches the subconscious, as all such warrens do. Tunnels have an archetypal resonance; they are almost the physical expression of repressed memories. Naturally, they also have a great power over the imagination because we subconsciously associate them with the dead. There is an architectural echo between the egg-shaped brick tunnels that form the capital's oldest sewers, and old catacombs found everywhere. That, combined with all the underworld beliefs - from Hades to Hell - that have been with us since the dawn of history, makes staring into the blackness of a tunnel a cause for hesitation. Even the bigger tunnels - years ago, for instance, I once walked through a disused railway tunnel in Wales that was large yet also intensely claustrophobic - can feel like an inhumation chamber. Elsewhere, every so often, there are guided tours of the old catacombs in Victorian Kensal Green cemetery. When it was first opened, coffins were lowered below by means of a revolutionary hydraulic lift. The high-pitched noise it made terrified locals, who thought they were listening to the souls of the recently departed. So thank the heavens for dedicated professionals such as Mr Hailwood, of fatberg fame, who take pride in venturing into dark crevices. "It took Hailwood and the guys three weeks to flush this one out with high-powered water jets," said a Thames Water spokesman. But Hailwood and his team are not alone in their proud subterranean vocation. The towering achievements of the Victorian engineering pioneer Joseph Bazalgette - the man who brought London's sewers into being - inspire many today, all over the country. In Manchester, the Museum of Science and Technology has built a special recreation of the city's Victorian brick underworld. Meanwhile, recent documentaries about the London Underground have revealed a workforce with a ceaselessly cheery enthusiasm for the Stygian depths. This goes way back. There is a fascinating short film made in the Fifties about the men and women who worked after midnight in those old Tube tunnels, including the "fluffers," doughty ladies whose job it was to keep the tunnels as free as possible from dust, paper, and hair. These days, the job is done by a vacuuming machine. Though rumours persist of special teams of covertly employed women. But as the Kingston fatberg demonstrates, we are subjecting our sewage pipes to abuses they were never designed for: the disposal of ever-increasing volumes of cooking fat and wet-wipes. Glasgow's Victorian sewers have recently been confirmed for an extensive upgrade. But in London, there is still noisy bitterness over the forthcoming construction of a new sewage super-tunnel. What's proposed is an epic capital-wide project. Opponents all along the proposed route from West to East are concerned about the massive disruption the excavations will cause to riverside life. Yet this work is probably the least of what has to be done to ensure that Bazalgette's proud legacy remains intact. Over the next few years, as urban populations rise, there will be fatbergs from Manchester to Birmingham. There will also be moaning about the cost of upgrades and the inconvenience. But there is nothing else for it - we must get on with it. The thing to do is to borrow some of Bazalgette's vision: for thanks to him, those noisome caverns still have a most unlikely sense of romance about them.