World's leading riders on show as Greenwich hosts first test run

Greenwich Park was transformed today as an equestrian test event for the Olympics got under way.

The competition, featuring 40 of the world's leading riders, was the first big event in a series of dry runs to prepare venues for the Games.

The surface of the main arena has been built on a custom-designed platform to achieve a flat field.

This is the first time this system has been used in an equestrian competition. A lightweight temporary arena has been erected to host dressage and jumping, as well as laser shooting for the modern pentathlon world cup final event at the weekend. A cross-country course has been installed on the east side of Greenwich Park.

Organisers said it would give spectators the chance to see some world-class equestrian events while also allowing athletes and team officials to compete at the venue ahead of the Games. They will be able to give feedback on the plans. London 2012 chairman Lord Coe said: "We have worked hard on the detail and will treat the park with respect and care."

But conservationists claimed that about three-quarters of the park had been blocked off for the event and that its use next year would cause irreparable damage to the World Heritage site.

The Duchess of Cornwall is set to attend a reception for sponsors and competitors tonight in her role as patron of the British Equestrian Federation before returning to watch the events on Wednesday.

Protesters say they plan to target the event to coincide with her visit.

Susan McNeill, 52, a committee member for NOGOE - No to Greenwich Olympic Equestrian Events - said: "Three-quarters of the park is out of bounds, it's like a prison camp."