The original gardens were created for Augusta, Princess of Wales around her home, Kew Palace. She was much helped by Sir William Chambers who was influenced by oriental gardening and designed the Chinese pagoda in the grounds and other buildings. The estate was acquired by the nation in 1841 and enlarged to become a place for the scientific study of horticulture. It now contains the largest collection of plants in the world with tropical and sub-tropical plants being kept in appropriate conditions in magnificent Victorian glasshouses. The variety of plants is overwhelming but Kew has a magic far above the ordinary run of Victorian plant collections, perhaps because of its size and the underlying but unobtrusive formality of its structure. The Queen's Garden is a faithful copy of a 17th century garden with parterres, sunken garden and pleached alleys. A new treetop walk by Marks Barfield Architects (who designed the London Eye) opened in May 2008. The walkway is a steel structure, 200m long and 18m high.