The world's best Eventing riders will tackle Benson's 6km course on 30 July.
It promises to be the pivotal phase of the competition and will complete a lengthy project for 60-year-old Benson.
'At that time (five years ago), the trees and the roads got in the way of my vision, but I then realised what a unique site it was,' she said.
'I struggled with the initial concept, but saw that it could be something very special. It's an inspirational site.
I wanted to represent the park and London, but it developed beyond there.Sue Benson
'I wanted to represent the park and London, but it developed beyond there.
'The iconic vision became "let's do England", but the fences must still fit comfortably within their environment without it becoming a theme park.'
Much has been made of the course's tight and twisting nature over its 10-minute duration, suggesting it will be an entirely different challenge to what most riders are familiar with.
'The real challenge was creating a track that used the hills but, in the end, to have enough gallops for the riders to enjoy the course,' she added.