In 1962, Greenaway began studies at Walthamstow College of Art, where a fellow student was musician Ian Dury . Greenaway trained as a muralist for three years; he made his first film, Death of Sentiment, a churchyard furniture essay filmed in four large London cemeteries. In 1965, he joined the Central Office of Information (COI), working there fifteen years as a film editor and director. In that time he created a filmography of experimental films, starting with Train (1966), footage of the last steam trains at Waterloo station (situated behind the COI), edited to a musique concrète composition. Tree (1966), is a homage to the embattled tree growing in concrete outside the Royal Festival Hall on the South Bank in London. By the 1970s he was confident and ambitious and made Vertical Features Remake and A Walk Through H. The former is an examination of various arithmetical editing structures, and the latter is a journey through the maps of a fictitious country.