There is a little corner of Perthshire that will forever resemble Brigadoon.
It emerges from the mist early on Sundays and evaporates with the afternoon sun.
It is the Errol car boot sale, a once-a-week pop-up phenomenon that vanishes almost as quickly as it appears.
You can drive along the A90 between Perth and Dundee early on a Sunday in complete serenity.
Yet a couple of miles from the dual carriageway, a clattering hub of commerce is getting into full swing.
By 8am, deals are being struck on long-forgotten attic toys, there’s a bloke auctioning meat from a portable butcher’s shop, field kitchens are frying up chips and cheese, while mountains of pet food, Brendan Shine DVDs and steel toe-capped boots are being offloaded in old aircraft hangars.
It is like a hidden, parallel world. It is difficult to comprehend how thousands can gather and disperse so quickly and with such little fuss.
If you’ve watched Harry Potter, the boot sale will remind you of a mixture of Diagon Alley and the Quidditch World Cup campsite.
It is daunting for newcomers. As soon as you open your boot the crowds are in there raking, jostling for first call on any jewellery.
The experience is shocking until you realise it is all a game. Buyers try to act like ultimate bargain hunters, sellers respond by trying to drive a hard deal.
It is a culture that must have evolved over many years but it produces good-natured results.
Entire families make it a day out. Errol becomes a mixing pot of local cultures Dundee, Perth and Fife, a bit like a camp on an old drover’s trail. Then the hundreds of eastern European youngsters add an international dimension.
It can throw up many a surprise too. My cousin once found an exam certificate belonging to my father’s fearsome but long-dead aunt. How my father rejoiced when he was reunited with that!
You won’t make a million but four hours standing chatting in the fresh air sharpens your appetite for chips and cheese or even better, a world-beating bacon roll from Kenny Farquharson’s Horn milk bar.