It is as British as cups of tea, the Queen, and unnecessary apologies.
Visitors to Great Britain learn the moment they cross an airport threshold there is but one sacred British tradition all must abide by.
British queueing is a high art form. It is a source of national pride. It is the one topic the entire nation is in agreement on in these uncertain times.
So when the balmy Good Friday weather brought a glut of hikers out to the Brecon Beacons on one of the hottest days of the year so far to make the famed Pen y Fan peak climb, they knew what to do.
Alan Dawson snapped the "orderly queue" waiting ever so politely to have their picture taken at the summit.
He tagged it: #onlyinbritain, reports Wales Online .
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The climbers all faced a long wait to get the memento of their 886-metre climb.
But showcasing the finest spirit of British etiquette, they queued up and patiently awaited their turn.
Ben Maizey was also at Pen y Fan. He witnessed that most British of phenomena, and he knew what to do.
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He tweeted: "The most British thing you'll see on a bank holiday: people queuing orderly at the top of a mountain just to take a photo. And yes, I have just joined that queue."
As visitors to these fair isles often note, Brits just love to queue.
It once even made the top five of the 50 British traditions we are most proud of.
According to a luxury holiday provider's survey of 2,000 Britons, "the ability to queue nicely" came in at number four - after traditional roast dinners, "putting the kettle on in a crisis," and eating a full English breakfast.
Naturally, that other great British tradition of "tutting or sighing loudly if someone jumps a queue, but not doing anything about it" was ranked in 31st place.
Unfortunately the British talent for queueing has never quite extended to the roads, as visitors to Pen y Fan found today.
Drivers faced problems parking at the bottom of the mountain as cars were left parked on verges, Wales Online noted.
Motorists were spotted lining both sides of the A470 as they struggled to find a parking spot.
