“To count as a Thomasson,” says Ettel, “an object must be completely purposeless but also maintained,” hence the parallel with the Yomiuri Giant who was “on a huge salary but [who] never hit a ball”.

Wong Kar-wai the inspiration behind students’ novel architectural photos

Thanks to continuous demolition and rebuilding, you might think Hong Kong would be a target-rich environment for Thomassons – and you’d be right. Ettel and his students have form in exposing its wealth of quirky and amusing urban architectural leftovers: witness their July exhibition Beyond What We See, held at PMQ, Central, on which the TEDx talk will expand.

While other books and podcasts have exported the phenomenon to much of the world, Ettel believes Thomasson-spotting, except in its homeland, hasn’t really caught on in Asia.

“It’s such a Japanese thing, famous since the ’70s,” says Ettel, “but rare in other cities in Asia and never really tested in Hong Kong until we had the chance. It was a brilliant exercise: the students had to look up and around – and away from their phones – and you can’t just Google Thomassons. They had to be curious about the city and question why things are the way they are.”

Redundant street furniture extends to flower-planting areas covered by concrete slabs, pedestals for long-gone street lights and no-parking pillars marooned on pavements. Mysterious rusting brackets poking from walls, roads to oblivion and air-conditioner canopies with nothing to protect, plus assorted bollards, balconies and barren metal frames add baffling flourishes.

Public conveniences have also left their mark. A squat toilet can be found among the remains of Kung Man Village, below Mount Davis; and in Sai Ying Pun, a stone wall containing concrete-filled windows that separates Queen’s Road West from a slope up to adjoining properties is what’s left of a 19th-century toilet built for local workers. (The slope, incidentally, is otherwise known as Bird Bridge and the wall is also a former sea wall.)

“We found interesting things that go way beyond any narrow scope,” says Ettel. “And Akasegawa was very open-minded and more interested in the conversation than just, ‘This is the definition.’ For him it was really more like, it’s a collaborative project, everybody should go out and find Thomassons and if you come up with a better definition and expand the understanding of them, it’s part of the discussion.

“So I’m in the tradition of keeping it all alive rather than telling people what is or isn’t a Thomasson – that doesn’t really help us,” says Ettel.

Then again, a city’s age is no guarantee of a ready supply of Thomassons. Ettel’s native Vienna offers surprisingly few – partly, he believes, because the city authorities prefer neatness to obsolescence.

New and relatively new buildings, meanwhile, are not excluded from the party: witness Kennedy Town MTR Station, whose Exit B offers a couple of tucked-away, miniature steps just big enough for a two-toddler crèche.

While most Thomassons hide in plain sight, some are disguised and chanced upon, perhaps in shock. This correspondent once rejected the opportunity to rent a flat whose bedroom window, when opened five centimetres, clanged lustily into the back of a neon sign that proudly blazed over Causeway Bay the attractive qualities of an edible oil.

That chimes with another point that Ettel intimates: Thomassons are really products of the intricacies of property ownership, changing land use, long-term building development, subdivisions or government budgets. And sometimes, their very presence throws us a puzzling curve ball.

TEDxHKU Kaleidoscope 2021: November 6, 2pm-6pm, Yuet Ming Auditorium, University of Hong Kong, Pok Fu Lam. For information about tickets email: [email protected]