I’ve worked in a Path-connected building for over a decade, long enough to remember a time when it had smoking rooms. A couple of years back, I began to notice a guy sitting outside my building, wearing cargo shorts and a T-shirt, huffing a brick-sized vape while gaming on his phone. Summer turned to fall turned to winter, and still the shorts remained, his aloof pose untempered by the sleet or snow. He seemed to me to embody the apotheosis of Pathitude. For him, weather seemed an obsolete curio of a less-evolved time.

Take a walk through Toronto’s financial district and you probably won’t realise that you stand atop the largest underground shopping complex in the world. You might see the occasional doorway at street level bearing the words “Retail Concourse” in a nondescript font, but for the most part the more than 100 entrances to this labyrinth, known as the Path, are accessible only from within the office towers.

The stats certainly inspire awe, of a sort: 30km of networked passageways; 75 connected buildings; 1,200 stores, eateries, and services; 200,000 daily users; 4m sq ft feet of retail; C$1.7bn (£1bn) in annual sales. But the Path is a monolith that at no point feels monolithic. When I asked a financial district-employed friend of mine how he felt about it, he could not muster a single feeling.

The Path is a labyrinth comprising 30km of networked passageways and 75 connected buildings. Photograph: Yuula Benivolski/The Guardian

Unlike the ornate subways of Moscow or the macabre catacombs of Paris, the Path does not call out for attention. It is workmanlike. Functional. A convenience rather than a destination, which its transformation into ghost town on evenings and weekends reaffirms. It’s largely beige in colour and in spirit. If the catacombs are Alien Sex Fiend, then the Path is Pearl Jam.

Though its magnitude suggests top-down urban planning, in reality the Path emerged patchwork-like over the course of a century

It is not a place for wanderers. People down here walk quickly, with a purpose in their step, whether they be power brokers or the support workers who service them. Rolling briefcases whirr along the marble floors. The morning rush hour introduces a crush of unidirectional movement from Union Station to the financial district; the workday’s end reverses this. Walter Benjamin and other members of the flâneur class would grimace.

Lunchtime is more chaotic, occasionally resembling a less intense Shibuya-style scramble. Many of the eateries, from the much-loved independent Korean joint HoGa to the French macaron vendor Laduree or any of the 13 branches of Starbucks, roll out an array of airport-style, retractable-belted stanchions to tame the swarms. Groups of people perch around laptops, proving that if some merely go directly from the boardroom to the food court, the true alphas bring the boardroom to the food court.

The network includes 1,200 stores, eateries, and services. Photograph: Yuula Benivolski/The Guardian

Across the world, these tunnel cities are spreading. Montreal’s Réso system is slightly bigger than Toronto’s Path, boasting 33km and 2,000 retail spaces, though in three disconnected sections. Sydney has one; Singapore, too; and Riyadh is building a pedestrian tunnel network above ground for the new King Abdullah Financial District.

Helsinki has probably dug furthest, with more than 200km of tunnels spread across 500 disconnected spaces, though only a small fraction of it is open to the public, with the rest used for wastewater treatment, energy distribution and other infrastructure. Helsinki is also the most playfully designed: undulating cave walls painted white are festooned with the occasional vertical garden, and there is an underground museum, church, swimming pool, and hockey rink – just the sort of thing that gets brought up when people speak idealistically of the Nordic countries.

But in terms of sheer continuous commercial distance, Toronto remains king. Though its magnitude suggests top-down urban planning, in reality the Path emerged patchwork-like over the course of a century. The first tunnel was built in 1900 between the T Eaton department store and its discount annex across the street (possibly in an effort to one-up Simpson’s, its rival directly to the south). By 1917, five Eaton buildings were connected. In 1929, a tunnel connected Union Station and the newly-built Royal York Hotel.

But it was from 1954, when Scottish engineer Matthew Lawson was put in charge of city planning, that Path began to take shape. Lawson foresaw overcrowded sidewalks, as the newly growing financial district increasingly privileged massive lobbies over street-level retail. He envisioned a connected, subterranean network as a kind of realpolitik solution: below-grade retail was exempted from density restrictions, promoting expansion downward, and the city also agreed to split tunnel construction costs with the building owners.

Path transformed what would otherwise be reasonably cheap and undesirable commercial basement real estate into some of the priciest in the country

The cost-splitting was revoked in 1976 by a reformist city council, hostile to such megaprojects, but by then the flurry of financial district construction had rendered it moot: Commerce Court West, First Canadian Place (still Canada’s tallest office building) and the multitower Mies van der Rohe-designed Toronto-Dominion Centre each had its own underground shopping concourse, with further connections between buildings proliferating throughout the 1980s.

The Path as we know it today was unified in 1995 by a thoroughly ineffective wayfinding system – small grey signs that only directed you to the building immediately adjacent. The ineffectiveness was partially by design. Property managers worried that if certain routes were encouraged over others, non-artery retail would suffer and rents would fall. And so commenced the tension between the Path’s civic and commercial interests, between people trying to get from point A to point B and the property managers who wanted people shopping in their stores.

The Santiago Calatrava-designed Brookfield Place office complex in Toronto. Photograph: Gary Hershorn/Getty

A new wayfinding system has improved matters somewhat, but just as Berlin superclub Berghain forgoes mirrors (or reflective surfaces of any kind), the Path still forgoes the concepts of north, south, east, and west. The signs never explicitly tell you which way you’re going, barring a few hard-to-find compasses on the ceiling. The psychic fencing has proved effective: show me a person who can effortlessly walk the two kilometres from the Toronto Coach Station to the waterfront and I will show you an obsessive.

Some have wondered if more explicit nods to the compass would even do any good. Since its layout is dictated by the vertical architecture of the buildings above, only tenuous homage is paid to the street grid. And despite its pastiche of architectural styles, you’re generally overcome by the crushing sameness of it all. The white Italian Carrara marble of First Canadian Place gives way to the Swedish Red Napoleon granite of Scotia Plaza, but there aren’t really landmarks to sink the teeth of memory into, though there are at least 20 Tim Hortons.

Still, there are pockets of grandeur. Climbing up into the galleria of Brookfield Place’s six-storey parabolic canopy could certainly be called grand. Similarly, entering the Royal York’s ornate lobby from below, where duelling winding staircases rise along opposite halves of a large circular floor slice, verges on cinematic. Meanwhile, Van der Rohe’s aesthetic exactitude shapes the passageways beneath the Toronto-Dominion Centre in arch-modernist style: shops with the glass panels, black aluminium and backlit white lettering selected by Mies, right down to the austere sans serif font. The rules were relaxed in the 1990s, however, ruffling the feathers of Bauhausian purists and peppering the window displays with all manner of multi-coloured graphical cringe.

But for many the Path is a place to work. So what of those workers,some 6,000 of whom toil in the Path’s sunless hallways?

“The worst job I ever had was being a barista down there,” said a friend who logged two years at the Path outpost of a local cafe chain. “I would cry in the washroom a lot. It feels like a classist dystopian hellscape.

“As a service worker you’re essentially ignored by the business people. But there is a solidarity,” he said. “We traded food and drinks with other businesses. Janitors are assigned one hallway that they mop all day long, so you get to know them really well and build a bond because they’re also mistreated or invisible. In the winter I would go down when it was dark and leave when it was dark and wouldn’t see the sun.”

Katie Whittaker, owner of the non-Path bar Thirsty and Miserable, used to work at an LCBO (the government-owned liquor retailer). “We sold lots of 375ml bottles of vodka to businessmen at the Royal Bank Plaza store,” she said. “They would buy handfuls of them at once. Handy for GO Train commuting back to the ‘burbs. Also easy to hide drinking in the office.”

In these and other ways, the Path feels less Jane Jacobs – the champion of messy street-level urbanism who adopted Toronto as her home – than Robert Moses, her arch nemesis from New York, albeit minus the wanton bulldozing and mass displacement of minority communities. But its patchwork nature and loose public/private partnership does more or less chime with what some have called Jacobs’ crypto-libertarian tendencies: other than the unified signage, the city has taken a hands-off approach, with daily management left up to the buildings. The Path is also reserved exclusively for pedestrian use, where Moses’s large-scale interventions were predominantly in service of the automobile. Still others might say that pushing pedestrians underground demonstrates an abject and total capitulation to cars. This summer, members of the Financial District Business Improvement Area conducted a Jane’s Walk tour to attempt to square the Path with her legacy: whether cynical appropriation or earnest effort is anyone’s guess.

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Perhaps the Path’s most galaxy-brained move was one in the service of the financial district’s property managers. It transformed what would otherwise be reasonably cheap and undesirable commercial basement real estate into some of the priciest in the country. With most denizens not straying more than a couple of buildings away from their own, the Path mirrors the consolidation of internet traffic by the big tech of Facebook, Google, Amazon and Youtube, in which the idea of an endless frontier is more attractive than actually treading beyond the horizon.

And still Path expansion continues unabated: it now reaches south of the financial district, right up to the cusp of the waterfront, with plans to extend it further east along the lake. Construction has begun on another tunnel, connecting the HSBC building directly to Union Station. The city’s endless condo boom promises to eat up ever greater swaths of the downtown core, and it is not hard to envisage our netherworld expanding along with it. In the future we may all be wearing cargo shorts to work as the frost sets in.

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