London Clay Journeys in the Deep City

We walk on layered history. The ground beneath our feet is shot through with traces of our past, some in plain sight, many buried and badly eroded. Writer and artist Tom Chivers will concur that nowhere is this more true than in cities. London Clay is the result of a decade of exploration on foot, tracing vanished rivers, lost islands, and geological strata hiding under the concrete bedlam of modern London. The city's untidy edges, its brownfields and derelict buildings, the very lay of the land – in Chivers's hands all of these become cracks through which the past oozes back in. An unlikely chimaera of nature writing and urban exploration, this lyrical book offers a fresh way of looking at the built environment.

The genesis of this book is hard to pin down. Born in South London in 1983, Chivers has been fascinated since childhood with exploring the city. Throughout his twenties, he continued to chronicle London through barely-read poems, pamphlets, and books. Just as this creative impulse was petering out, arts charity Cape Farewell approached him to be their first poet-in-residence, in turn leading Chivers to produce a series of audio walking adventures along London's lost rivers. This, if anything, provided the impetus for the writing of London Clay.

In eight chapters, the reader follows Chivers as he walks the course of now invisible rivers. South of the Thames: the river Effra and one of its arms, the Ambrook, into Dulwich and Sydenham, the Neckinger into Southwark, or the lost island now subsumed in the district of Bermondsey. North of the Thames: the river Walbrook into Broadgate and Shoreditch, the river Fleet all the way into Camden Town and Hampstead, the former delta on which Westminster was built, or the Lower Lea Valley in Stratford and Hackney that hosted the 2012 Summer Olympics.

If, like me, you are not a Londoner, you might be unaware that there is quite some interest in its subterranean rivers, the bricked-over tributaries of the Thames. At a young age, Chivers already laid his hands on Nicholas Barton's 1962 book The Lost Rivers of London, and he later takes Tom Bolton's 2011 London's Lost Rivers with him. However, London Clay is not a walking guide: although each chapter is preceded by a map, these outline geological strata and a few modern and historical landmarks only. One might be able to retrace Chivers's steps, but it would take some puzzling. It is also not a photographic book akin to Paul Talling's London's Lost Rivers, instead relying on some atmospheric illustrations by Rohan Daniel Eason. Similarly, Chivers walks largely aboveground, at no point crossing paths with the urban exploration scene that crawls through London's sewers and tube tunnels. And although he ends up on the intertidal shores of the Thames more than once, mudlarking only features sparsely.

Instead, these are a poet's ramblings, tracing "a procession of ghost-lines retreating in time" (p. 67), following the meanders of barely visible channels, "the desire line of water" (p. 69). Chivers calls it an exercise in "deep topography", linking to what Nick Papadimitriou did for London's outer limit in his 2012 book Scarp. Or, I might add, what Iain Sinclair did before that with e.g. his 2003 book London Orbital. Effectively, Chivers's book is part of a fairly young tradition of writings on psychogeography, an arts term for the effect of place on our emotions and behaviours.

Next to this, without wishing to sound snooty, there is also a fair bit of amateur sleuthing in here. Chivers excuses himself for being "neither historian nor geographer, but [writing] with the poet's compulsion for rumour and conjecture" (p. 6). He delves into books and maps, traces the linguistic origin of place names, and accompanies caretakers, local historians, and archaeologists as he walks the city. Several historical periods feature prominently. One is, logically, the late 19th-century construction of London's sewer, overseen by engineer Joseph Balzagette – this is when many waterways were incorporated into the sewer system and disappeared from sight. Chivers is furthermore attracted to the sites of former Tudor-era playhouses and theatres, such as The Boar's Head in Whitechapel, or The Rose in Bankside that is currently sheltered in the basement of an office block. And remains of Roman and later Anglo-Saxon London keep surfacing during construction projects.

Further back still, Chivers delves into London's geology. "Geological time reduces the human story to a footnote in the history of the planet [...] This London is rarely seen, but it is always there, pressing its immanence into our world" (p. 5), he writes. It is his channelling of deep time that most brought to mind Robert Macfarlane's Underland, from which he quotes on several occasions (and of which London Clay‘s cover reminded me). There is even a surprise appearance of a young Patrick Nunn. Chivers describes his 1983 idea of how the Thames, as climate and sea levels changed over thousands of years, "slowly progressed north, like a snake coiling and uncoiling, before reaching the meandering form we know today". In turn, this "left behind a series of 'relict channels' and some of these subsequently flowed as tributary streams – the so-called lost rivers" (p. 274).

It is tempting to draw comparisons to Neil Gaiman's London as it features in Neverwhere. But I was foremost reminded of China Miéville's The City & The City. Here, two cities entwine, with citizens overlapping in contact zones. Yet, from birth, they learn to not just ignore but to studiously unsee their counterparts. An Orwellian government organisation strictly monitors for cases of Breach, rounding up anyone who accidentally or purposefully interacts with the other side. It is exactly the way Chivers's writing seamlessly transitions from now-London to past-London that evokes this, laying bare a city that lies in plain sight but that most of us do not see.

By offering a model for how to look at our everyday environment with a different set of eyes, London Clay might just foster a renewed sense of care and custodianship in city dwellers. Even if it would not achieve this lofty goal, it is an entrancing book that, though steeped in London lore, is fascinating even for those of us not living there.