Mistaken identity and a covert social experiment are among reasons suggested for the sudden appearance of tourists in an Oxfordshire village.
"Coach loads" of sightseers in Kidlington have been seen posing for photos in front gardens and against parked cars.
Locals have no idea why the quiet suburb, about five miles north of Oxford, has become a tourist magnet.
Many people have taken to social media to put forward theories.
Meanwhile, local residents have reported some of the new visitors have been making themselves at home.
One said tourists had knocked on their door asking to use their toilets, while another found visitors sat on benches in their garden eating packed lunches.
Resident Nick Allington, 66, said the tourists asked one family if they could cut the grass in their garden.
He said: "It's a mystery that I'm not sure will ever be solved."
The tourists, who have been showing up for three weeks, were first identified in Benmead Road and the Moors, the Spotted: Kidlington Facebook page revealed.
They are a short walk from thatched cottages and an old church, but prefer taking photos of themselves outside modern houses.
It has been suggested that sightseeing tours could be mistaking Kidlington for Kirtlington, which is nearby and describes itself as "a quintessential English village".
Another theory centres on the Japanese title for an Inspector Morse novel, which translates as: "Disappeared from Kidlington."
Michelle Young, who lives in The Moors, Kidlington, says they did try to solve the mystery.
"A neighbour did try to ask them where they were from but they didn't speak any English and we didn't get very far," she said.
Baz Daniels, who has lived in Kidlington for more than 20 years, said he had been in touch with a friend in China to try to get to the bottom of the tourist influx to his village.
"Kidlington is apparently being marketed by Chinese tourist agencies as a beautiful English village on the way to Bicester Village shopping centre," he said.
"Many of the visitors live in cities, and love to see things like the hanging baskets and little flowers in people's gardens.
"Visitors are now actively asking to add Kidlington to their tour itineraries," he added.
Lying in wait
By Joe Nimmo, BBC News
It's all quiet at the scene here in Kidlington, with no sign of any tour buses or sightseers.
Everyone I've spoken to has been more amused than annoyed by the groups regularly turning up. And thankfully that attitude also extends to large numbers of reporters and cameramen.
It's certainly a very well-kept area, with smart lawns and gardens, as well as lots of colourful flowers.
If the tourists were looking for a good example of a suburban English street, they couldn't have done much better.
Kevin Grealey said he thought it was "some kind of social study done on the quiet by students of Oxford University".
Andrew Huddart said it could be a "folksy cultural stop" between the popular tourist destinations Bicester Village shopping centre and Oxford University.
And Andrew MacLachlan said: "They are time travellers, something terrible must happen to your village when we finally exit the EU, they just want to see Kidlington before the event."
Inspector Morse, Midsomer Murders, Love Island and Harry Potter are also among the causes suggested for the tourists' interest.
People pointed out billionaire Sir Richard Branson and Emma-Jane Woodham from ITV's Love Island had connections to the Kidlington area.
Others wondered whether the groups were judging Kidlington in Bloom.
Emma Layden suggested: "Perhaps it's because Kidlington is claimed to be England's biggest village?"
Highlights of Kidlington
- London Oxford Airport, otherwise referred to as Kidlington Airport, is described on its website as the Thames Valley area's "primary regional and business aviation airport"
- Thames Valley Police and Oxfordshire Fire and Rescue Service's headquarters
- Campsfield House immigration centre - Campsfield House has been an immigration centre since 1993 and is run by Mitie on behalf of the Home Office