RIYADH: Some of the most expensive horses in the world have been flown into Saudi Arabia ahead of the Longines World Champions Tour in Riyadh.Transported from Belgium, the European horses arrived at King Khalid International airport in the Saudi capital on Monday and have been moved to the event venue at King Abdullah Financial Center. The event, which is taking place between Oct. 26 and Oct. 28, will crown four champions, with team and individual competitions. The stables at the venue can accommodate more than 300 horses and is monitored round the clock to ensure the safety of the horses. There are 120 local horses taking part this year. Each rider and their assistants have been designated training times each day and the management committee has also set specific times for riders to enter the stables.