There seems to be no accounting for taste in architectural fashion. Shunned, condemned and demonised in its "lifetime", Kowloon Walled City was long considered a malignant blot on the progressive Hong Kong landscape.
Yet just 20 years after its destruction, the squatter camp has been transformed in the minds of commentators into a paragon of design - albeit organic - and the archetype of a workable, livable development underpinned by a sense of community among those who resided there. The truth is somewhere in between.
The man to shed light on the question of the resplendent monstrosity's ambiguous legacy is British architectural photographer and publisher Ian Lambot, who, along with Canadian photojournalist Greg Girard, published 1993's City of Darkness: Life in Kowloon Walled City.
"Going there was always an adventure," says Lambot. "I went to photograph it 30 or 40 times but you could never get to know it."
Theirs was perhaps the outstanding volume in a crop of discussions, dissections and dissertations published after the Kowloon boil was lanced. With the distance of history, however, the Walled City's reputation has become considerably more wholesome. So, in a new edition, to be published in July, Lambot and Girard reassess the complex subject of what was once the most crowded place on the planet.
What exactly was in the high-rise shanty town's (non-)design DNA that allowed it to remain standing, let alone function as a society all its own? "From an architectural perspective, Kowloon Walled City was totally unplanned - it was architecture without architects," says Lambot. "There were no studies or consultations; residents just got on with it, mucked in and found solutions. That is how the city evolved into a warren of winding corridors and a multitude of levels," he says.
The residents, numbering about 33,000 when the city, at its most bloated, offered each person living space of 30 square feet, were unwitting rebels.
"The modernists of the '30s and '40s saw architects as gods who designed everything: buildings, chairs, doorknobs. Le Corbusier took city planning to a new level. In the '60s and '70s there was a reaction to that, and architects began looking at traditional buildings and how they allowed people to get on with things," says Lambot.
"It was decided there was too much city planning and that, in fact, cities grew organically; the people who lived in them should decide how things should be."
Which brings us to the haphazard growth of the Walled City and its peculiarly apposite place within, and yet without, the urban area surrounding it.
"The Walled City was a microcosm of Hong Kong architecture," says Lambot. "Thanks to the lack of space it had the same constraints.
"Mixed-used buildings - restaurants, offices, residential - were far more prevalent than in the West, which is down to [the latter's] very detailed over-planning. And that destroys a city because you have to go everywhere by car," he says.
"Because of its constraints, Hong Kong is the same [as the Walled City]; you have to pile it all together, as in the old shophouses: shops on the ground floor, living space above.
"And now the West is looking at Asian cities as a model. In Holland, buildings are being designed with big spaces in which people can take parts of floors to live and parts to turn into offices," Lambot says.
The trend is also detectable much closer to home. "Here, in places like Chai Wan, people are buying space in old godowns and turning it into apartments," adds Lambot. "It's a legal grey area, but the government is turning a blind eye. In China, on the edges of big cities, you have urban villages that are almost copies of the Walled City.
"Migrant workers are not allowed to own or rent where they are employed because they're not residents. So they put up their own buildings on wasteland. You see it in Shenzhen, Shanghai, everywhere. They're called 'handshake buildings' because if neighbours were to lean out of their homes, they could shake hands.
"These are straightforward, eight- or nine-storey buildings. Simple boxes, with shops at the bottom, or workshops, residential above. Space is limited so the density is the same as in the Walled City - although they are tidier and they don't cover the alleys.
"And there's daylight. Otherwise they're identical to the Walled City, which was a squeezed, condensed version of all these discussions about how you allow people to plan their own buildings," he says.
Nor has the Walled City lost its ability to inspire. In 2012, designer Joey Ho won a commission to build four distinctive private homes in Kowloon Tong that maximised use of the confined area while creating interior space.
"I realised the ultimate high-density homes had been in the Walled City," says Ho. "It was like a sponge - it was absorbent way beyond normal, making it a cube that wasn't fully solid. So I had an idea for a 'solid and void' module. We created houses of four floors and roughly 10,000 square feet each, with swimming pools and terraces. The client [a developer] was very happy."
The Walled City began as a Qing dynasty military outpost that was subsequently beefed up into a fort. It remained a Chinese enclave when Britain took out a 99-year lease on the New Territories, after which it was formally governed by neither.
Squatters seized the chance to settle around the old administrative office - the yamen - which is almost the only fragment of the City that still exists.
Their numbers boomed in two major phases. The first was when local refugees took shelter from the invading Japanese in the second world war (the Japanese demolished the eponymous walls for use in extending the Kai Tak runway); the second was in the 1950s and '60s, when hundreds of thousands of mainland refugees poured into Hong Kong.
Its 300 or so interconnected buildings crammed into one enormous block were handmade, says Lambot.
"The cement was hand-mixed. It all amounted to what you and a few friends could build. Space constraints meant you were forced upwards, not sideways as in most shanty towns, like in Mumbai or Rio. That was critical to the look of the city - the single-room-wide tower." These reached as high as 17 storeys.
There were no regulations, no master plan, foundations or plumbing. The water came from standpipes, and all the electricity was stolen hazardously from the grid supplying the outside world.
The book City of Darkness revealed, however, not a slum, but an ordinary community moulded by extraordinary circumstances, with factory, restaurant, brothel, living room, drug den and convenience store all cheek by jowl. However, Lambot admits, "Living there certainly wasn't easy, and could be hell." He recognises that, in our appreciation of the successes of the Walled City, we may be guilty of the "romanticisation of ruins".
City of Darkness Revisited, which is being funded partly by a Kickstarter campaign ending on April 18, contains much that's new to say about the city's architecture, largely mythical triad terrors, legal status and extensive pop-culture influence on movies, computer games and art.
But for all that, you'll have to read the book.