Alex Hua Tian of China competes the Equestrian test events for the 2012 London Olympics at Greenwich Park, in south London, July 4, 2011. [Photo/CFP]

LONDON - One of the London 2012 organising committee's most challenging venues was given its first dry run on Monday when the controversial equestrian arena in historic Greenwich Park hosted 40 of world's top riders.

The initial feedback from London's first test of any of its purpose-built Olympic facilities was positive with the unique raised arena, an engineering first in the sport, and the central location just a short trot to the city given the thumbs up despite some local opposition.

Many of the riders, including two-time British Olympic silver medallist Pippa Funnell, brought younger horses to the event, rather than their veterans, partly to give their less seasoned animals a taste of an Olympic venue, but also to gauge what issues may arise.

"The surfaces seem very good. We've got no complaints," she said after completing her dressage performance.

"We had to be seen not to be bringing our more experienced horses as it is a test event. It's a test obviously for the officials. It's trying to give our feedback as riders of what we've experienced over the years."

The three-day event, a gruelling trial that challenges the harmony between horse and rider and their stamina and strength, includes a dressage test, a cross-country course and finishes with show-jumping.

Riders and horses from 23 different nations congregated alongside the Royal Observatory, the Meridian Line and the National Maritime Museum for the competition, which organisers hope would be a litmus test of all the event's logistics, such as timing and scoring technology to stabling.

For the riders, the raised arena, where the dressage and show-jumping will be held, was a key part of the dress rehearsal, because of its innovative design.

An equestrian competes during the test events for the 2012 London Olympics at Greenwich Park, in south London, July 4, 2011. [Photo/Agencies]

Located in front of the Queen's House, with the skyscrapers of the Canary Wharf financial district in the distance, the ring has been fitted using adjustable legs as no holes can be dug in the park ground.

The London Organising Committee (LOCOG) have strived to keep the impact on Greenwich Park to a minimum during the test but community action group No to Greenwich Olympic Equestrian Events (NOGOE) has been busy collecting 13,500 protest signatures, insisting the park is unsuitable and that the events should be moved elsewhere.

One of the issues riders have brought up at past Olympics has been how the equestrian events, because of the sheer size of the facilities needed, are often hosted away from the main hub. In Beijing the equestrian events took place in Hong Kong.

German competitor Frank Ostholt said that although the venue felt small, it had so far been a good indication of what to expect at next year's games at which equestrian sport will celebrate its 100th anniversary in the Olympic movement.

"There is so much effort (the organisers) have put into this competition, into this test event and I'm really looking forward to next year," he said. "It's a little bit of a small area, but on the other side, it's amazing here, with the view over London and . It's lucky to be part of this as an equestrian."

"The challenge for me was mainly to be here and get used to the facilities. I have an eight-year-old horse so he's relatively young. He's performing well on this level and of course I can give him a good round."

The invitational in the Greenwich Park is the first large-scale fixture in the 12-month long London Prepares series of events in which more than 10,000 volunteers and 8,000 athletes will take part in the run-up to next year's Olympics, the third time the British capital will have hosted the Games.

"All of us have said you sort of have to kick yourself to think 'My God, I'm in the middle of London', and I think that is what is so unique and special and this is why next year it will be such an exceptional games," said British team member Funnell.