Aidan O'Brien has said that Found's win in the Prix de L'Arc de Triomphe was years in the making.

The filly led home a Coolmore 1-2-3 in Europe's premier middle-distance contest in what many are calling his greatest training achievement.

Speaking on RTÉ's Game On programme, O'Brien said that from her time as a 2-year-old all involved thought a lot of the filly.

She went to Longchamp last year but never got a clear run and connections were left wondering what was to be.

"From last year all the way through we had our eye on this," O'Brien said.

"We felt she didn't get a clear run this year and wondered what she could do."

This time around Found travelled well, with Ryan Moore guiding her safely around Chantilly - where the race has been moved due to works at Longchamp - and past the post.

"This is something you couldn’t even think of dreaming about"

"It was unbelievable," O'Brien said. "You could not believe it could happen.

"I suppose the Arc is one of those races you nearly think is impossible to win.

"We’ve found it very hard to win since Dylan Thomas won it a long time ago for us.

"It’s against all age horses and its very tough to win. It’s probably the toughest race throughout the year. You couldn’t really believe it could happen."

As impressive as Found's win is, the fact that O'Brien also saddled the second and third-placed horses - Highland Reel and Order of St George - makes it one of the greatest training feats of all time.

"It's very hard to beat this in any manner," O'Brien admitted.

"It's such an impossible race at this time of the season and such a competitive race. This is something you couldn’t even think of dreaming about."

Last year Found went on to finish second in the Qipco Champion Stakes at Ascot before overturning Arc winning Golden Horn in the Breeder's Cup Mile at Keeneland.

Despite Sunday being her eighth run of this campaign, O'Brien did not rule out a similar conclusion to the hard-working filly's 2016 campaign.

"For the next few days we'll think about where she goes to next. She has a choice of two races at Ascot, the Breeder's Cup, or maybe Hong Kong or Japan.

"We'll see how she is for a few days and then the lads will have a talk."