Organisers normally expect about 15,000 Irish race-goers every day, including expats living in the UK as well as people crossing the Irish Sea.

Star-spotting can be a full-time occupation, with many celebrity race fans making the trip, including a plethora of royals, actors and sporting figures.

More than 200,000 pints of Guinness are expected to be drunk at Prestbury Park as around 235,000 people attend the four-day festival. Punters are expected to wager €300m during the week.

The second day of the festival is traditionally Ladies Day, where women are renowned for donning stylish and glamorous outfits.

As well as prizes for the racing, there are awards for best dressed lady, best accessories and best hat, with an array of flamboyant head pieces, feathers and fascinators.

Other highlights during the week include the Queen Mother Champion Chase tomorrow, for which Sire De Grugy is favourite in the absence of racing’s top-rated steeplechaser Sprinter Sacre.

The meeting builds up to the Gold Cup on Friday, 50 years on from the first of three triumphs in the race for legendary Irish steeplechaser Arkle.

Today’s showpiece race is the Stan James Champion Hurdle with Ruby Walsh – the festival’s most successful jockey of all time with 38 winners – riding the champion Hurricane Fly.

Last year, the 10-year-old became the first horse since Comedy Of Errors in 1975 to regain the Champion Hurdle crown and, despite his advancing years, has shown no sign of decline in three starts this season.

With a world-record 19 Grade One victories to his credit, the Willie Mullins-trained Hurricane Fly bids to become only the sixth horse to land this sought-after prize three times.

“The festival is just different to any other meeting. I don’t know if it’s the crowd, the atmosphere, or the expectation, but there is something magical about Cheltenham,” Walsh said.

The horse rated by bookmakers as the biggest threat to Hurricane Fly is local hope The New One, trained by Nigel Twiston-Davies and ridden by his son Sam.

The going has been forecast to be good to soft, good in places for racing today.

Clerk of the course Simon Claisse said: “We have had very little cold weather during the winter and that has helped the grass growth.

“Although it has been dry here for eight or nine days, we had so much rain up to then that the course has held on to the moisture pretty well.

“It looks like the week ahead is going to be nice and warm and dry, which is fantastic for everybody.

“This place can dry out fairly quickly. In 2007, we went from heavy the weekend before to a Gold Cup run on good ground.

“We are going to take things day by day – there is a possibility that the ground will get a bit quick towards the end of the week – it depends on the breeze and what the temperatures get up to.”