The strangeness and the potential of immense urban conurbations to confront, confuse, surprise, delight and engage even the most knowing of city dwellers, is at the heart of Francis Alÿs’ work, whatever its subject and format. It oscillates in a space between fact and fiction, juxtaposing everyday contingencies of individual inhabitation with those more ordered physical and cultural manifestations, which have historically orchestrated and given structure to collective experience.

Operating at a range of scales and represented through a variety of media, his most recent major work, Seven Walks, is situated in London and was five years in the making. More of a process and method of engagement than a single coherent piece, it structures traversals across the breadth of the city, as well as focusing upon those sights and places which are, apparently, most familiar. Alÿs is a Belgian who lives in Mexico City and arrived in London as a relative stranger. Yet in some manner he recovers its iconography from the tourist and re-reveals it, both in its formal beauty and its bizarre ritual.

Collectively, the pieces fit into a long tradition of walking London, as a mode of both discovery and contemplation. Dickens traversals, both real and imaginary, or Henry Mayhew’s exploration and mapping of Victorian social deprivation, are just two examples of a historic fascination with walking as a means of beginning to come to terms with this unknowable city. Indeed, one can imagine that the dinosaur lumbering through the mist of High Holborn in the opening pages of Bleak House, could be one of Alÿs’ rumours.

Four of the Walks are recorded through annotated maps, photographs and postcards, in a manner that will feel strangely familiar to those who know the work of Richard Wentworth or Richard Long for example. In the simplest, Pebble Walk, the artist spends an hour and ten minutes walking through Hyde Park before counting the stones in his shoes. It openly acknowledges Long’s influence, yet the precision of the work is different. Whereas Long often reconfigures the landscape through which he moves, overlaying its topography with geometry, Alÿs seems happy to let chance play its part in the games he establishes.

In the more ambitious video and sound pieces, other issues come to the fore and yet the accidental continues to be allowed to adjust circumstances. In this they capture a central theme of Alÿs work - its operation within a kind of magical realism where the just possible, or what the artist describes as the rumour of something, becomes almost tangible.

In Nightwatch, CCTV cameras follow one of London’s urban foxes on a nocturnal wander through The National Portrait Gallery. Here it lingers under the haughty gaze of the 1st Viscount Bolingbroke, there it jumps up to return the disinterested stare of James II. The cameras look on, as unblinkingly as the portraits themselves.  It becomes difficult to understood exactly how real this is. Is it feasible that a fox might infiltrate this great institution, wrinkling its nose and waving its brush at those who, likely as not, had hunted its ancestors?  It turns out to be, at least in its instigation, a sort of fiction. The fox is an unwitting protagonist, moving freely but operating, for one night, within the structure of Alÿs’ project.

Displayed on a bank of 20 video monitors, arranged five by four, the form of Nightwatch suggests, at once, a surveillance system and a Quattrocento painting. In Guards, this neutral observation of overlayed structures happens at the scale of The Square Mile. It is a beautiful fable, where 64 lost and wandering soldiers in full dress uniform find each other, assemble into groups and finally come together as an eight by eight square, marching in echoing formation through London’s historic heart. Here, dislocated individual experience transforms into a memory of festival and historic ritual.

However, a wider and more contemporary political and social discourse also emerges. In their form and their recording, Nightwatch and Guards both critique issues of surveillance and control, obviously relevant in the context of London’s current situation. Similarly, in Railings, where the rhythms of London’s architecture, the columns and railings of its buildings and squares, become literal, through the beat of the artist’s drumstick as he walks against them, one is simultaneously reminded of how much of London’s urbanity is private and jealously protected.

It is in these correlations between wider cultural conditions and the coincidences and confluences of ones own memories and experiences, that the work is most powerful and most relevant. In juxtaposing order, knowledge and magic it becomes almost literally alchemic in recalling what we have nearly forgotten. From within the contemporary city, Alÿs is offering us a glimpse of other potential cities – from his Seven Walks we can begin to trace an eighth, our own.