ABC Online | Sydney's Royal Botanic Garden opens new $17m exhibition centre to celebrate 200th birthday ABC Online A permanent exhibition space has opened at the Royal Botanic Garden in Sydney to mark the garden's 200th birthday. The largest green living wall in the southern hemisphere at The Calyx exhibition centre in the Photo: The largest green living wall in ... On this day: Happy 200th to Sydney's Botanic Gardens Vendetta almost robbed city of its first botanic treasure Royal Botanic Garden botanist Dr Barbara Briggs celebrates 57 years |