Dusk and dawn sees Hanoi's leafy squares littered with devotees of da cau, Vietnam's ancient game of so-called "foot badminton" which endures despite the inevitable advance of football.
And it's not just the world's most popular sport that da cau enthusiasts must contend with: they also compete for space with people playing badminton, riding hoverboards or shaking their hips in a public zumba class.
But the da cau diehards say they are going nowhere.
"I do play football, but I find da cau more interesting," said Tuan Anh, who regularly leads a group of up to 50 people in central Hanoi at sunset.
The centuries-old game, which originated in China, involves keepy-up with a shuttlecock among any number of players for as long as possible, or knocking it over a net.
Though the game is enjoyed in public squares, it wasn't always a street affair.
Vietnamese emperors and feudal kings often encouraged soldiers to play da cau to improve health for battles, and to let off a little steam.
Da cau was also played to celebrate bumper harvests or traditional festivals.
Today it has become a national pastime, played by amateurs and professionals -- who dive and kick in spectacular style to keep the shuttlecock afloat.
Some say they are drawn to the cooperative spirit of the game, a way to unwind at the end of a long day at the office.
"Da cau is a team game. People play in clubs and teams, so it encourages teamwork and cooperation," said 24-year-old Nguyen Bich Hien, an employee at the Hanoi stock exchange.
"Going to the gym or walking, you have no companions, so it's not as much fun."
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