<P> With Prisoner of Azkaban, production of the Harry Potter films switched to an eighteen - month cycle, which producer David Heyman explained was "to give each (film) the time it required ." Chris Columbus, the director of the previous two films, decided not to return to helm the third instalment as he "hadn't seen (his) own kids for supper in the week for about two and a half years ." Even so, he remained on as a producer alongside Heyman . Guillermo del Toro was approached to direct, but considered the film "so bright and happy and full of light, that (he) wasn't interested ." Marc Forster turned down the film because he had made Finding Neverland and did not want to direct child actors again . M. Night Shyamalan was considered to direct but turned it down because he was working on his own film, The Village . Warner Bros. then composed a three - name short list for Columbus's replacement, which comprised Callie Khouri, Kenneth Branagh (who played Gilderoy Lockhart in Chamber of Secrets) and eventual selection Alfonso Cuarón . Cuarón was initially nervous about accepting as he had not read any of the books, or seen the films . After reading the series, he changed his mind and signed on to direct, as he had immediately connected to the story . Cuarón's appointment pleased J.K. Rowling who loved his film Y Tu Mamá También and was impressed with his adaptation of A Little Princess . Heyman found that "tonally and stylistically, (Cuarón) was the perfect fit ." As his first exercise with the actors who portray the central trio, Cuarón assigned Radcliffe, Grint and Watson to write an autobiographical essay about their character, written in the first person, spanning birth to the discovery of the magical world, and including the character's emotional experience . Of Rupert Grint's essay, Cuarón recalls, "Rupert didn't deliver the essay . When I questioned why he didn't do it, he said,' I'm Ron; Ron wouldn't do it .' So I said,' Okay, you do understand your character .' That was the most important piece of acting work that we did on Prisoner of Azkaban, because it was very clear that everything they put in those essays was going to be the pillars they were going to hold on to for the rest of the process ." </P> <P> Principal photography began on 24 February 2003, at Leavesden Film Studios, and concluded in October 2003 . </P> <P> The third film was the first to extensively utilise real - life locations, as much of the first two films had been shot in the studio . Some sets for the film were built in Glen Coe, Scotland, near the Clachaig Inn . The indoor sets, including ones built for the previous two films, are mainly in Leavesden Film Studios . The Hogwarts Lake was filmed from Loch Shiel, Loch Eilt and Loch Morar in the Scottish Highlands . Incidentally, the train bridge, which was also featured in the Chamber of Secrets, is opposite Loch Shiel and was used to film the sequences when the Dementor boarded the train . A small section of the triple - decker bus scene, where it weaves in between traffic, was filmed in North London's Palmers Green . Some parts were also filmed in and around Borough Market and Lambeth Bridge in London . </P> <P> Hogwarts grew and expanded significantly with the third film . For the first time, the Hogwarts courtyard and bridge were seen . At the end of the bridge, rock monoliths were placed onto the hillside to evoke a Celtic feeling . The use of live - action also significantly changed the look of Hagrid's hut . In the first two films, it appeared at the end of a flat stretch, right in front of the Forbidden Forest . The third film utilised the more rugged Scottish locations to place Hagrid's hut at the bottom of a steep hillside . A large pumpkin patch was added behind the hut . </P>

Where is harry potter and the prisoner of azkaban filmed