From the festival website:
"As part of the design process for [the Westonbirt International Festival of Gardens, 2003, David Meyer and his partner Ramsey Silberberg]
spent many hours considering what type of place the Arboretum is, its history and meaning, in order for their concept to resonate something about it.
Using a champion tree as the focus for their garden became clear. The crescent of the sculpted garden around the tree
hints at a medal round the neck of a champion, and resembles a classical amphitheatre -- a place to lie, reflect, admire."