It’s one of the greatest barn finds of all time — a collection of 60 cars, some rare and potentially worth millions, that was hidden away on an estate in western France.

The cars were collected by Roger Baillon, a French truck manufacturing magnate who purchased them and many more throughout the 1950s, ’60s and ’70s, then sold half the lot and left the rest to rot in 1978 when his business went bankrupt. They’ve remained untouched ever since.

The trove was discovered by a team of automotive specialists at the French auction house Artcurial who’d heard about it from a Baillon family friend. They were shocked that such an extensive stash wasn’t already on anyone’s radar.

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Among the finds are a Packard Super Eight Convertible, Bugatti 57 Ventoux, Delahaye Type 43 coupé chauffeur, a Hispano Suiza H6B cabriolet Millon-Guiet, and a Talbot Lago T26 Cabriolet Saoutchik that once was owned by King Farouk of Egypt. Many of the cars are one of a kind, custom-designed by famous coachbuilders of the day.

“I have to say that when we arrived here, we found ourselves overcome with emotion,” said Matthieu Lamoure, managing director of Artcurial Motorcars. “Probably much like Lord Carrington and Howard Carter on being the first person for centuries to enter Tutankhamen’s tomb. It really was a case of waking up Sleeping Beauty.”

Unfortunately, unlike Kings Tut’s treasures, most of the cars were stored under simple corrugated roofs and open to the elements, and all to some extent are worse for wear. The prize of the collection, though, a Ferrari 250GT SWB California Spider, was left in a garage and is in relatively good condition despite spending decades buried under piles of magazines.

The Ferrari had previously been owned by two French celebrities, including Alain Delon, who was photographed in it on separate occasions with Jane Fonda and Shirley MacLaine in the passenger seat. It’s one of only 37 made; a similar one in pristine condition sold at auction in August for $15 million.

Baillon had hoped to build a museum for his collection, but it was not to be. He died a decade ago, followed by his son last year -- the cars ending up in the possession of Baillon’s grandchildren. Instead, they will be displayed and then auctioned off during the annual Retromobile Salon classic car event in Paris in February.