Gloucesters historic cathedral cloisters were
transformed into the corridors of Hogwarts School of Witchcraft and Wizardry in the films of JK Rowlings first two books Harry Potter and the Philosophers Stone and Harry Potter and the Chamber of Secrets. There was the strictest of security to keep out the curious worlds press while filming took place but now some of the movie-makers secrets can be revealed. BBC Gloucestershire went Pottering in the cathedral with the Harry Potter trail guide and found that while Harry, Hagrid, Hermione and Ron may have moved on, there are still glimpses of Hogwarts magic if you know just where to look . . . Let there be (hidden) lights  | | Spot the hidden electrics |
All modern signs, locks and electrics had to be disguised under panels painted to look like the stone walls. Can you spot the cunningly concealed electric light switches inside the East Cloister door? Harry Potter and the Hidden Haloes For the films anything that would give away the set as a church had to disappear. The haloes on the stained glass figures in the cloister windows were painstakingly covered with coloured plastic filter paper to blend in with the surrounding glass. One window has figures of Adam and Eve, and because these might have been in shot in the movies, they were given clothes and even the trademark Harry Potter 'lightning flash' on their foreheads! Harry Potter and the Buried Tombs  | | These figures of Adam and Eve were 'dressed' and given forehead marks like Harry's |
There are nearly 100 tombstones on the cloister floors which had to be disguised during filming. They were covered with roofing felt, which was then painted, marked, polished, varnished and made to look faded to match the rest of the stone-flagged floor. Water Wizardry in Dark Entry The red door in Dark Entry, at the north-eastern corner of the cloisters, was where the flood from the girls toilets was filmed.  | | The Dark Entry doorway |
Water from a tanker parked in the road outside was pumped through the doorway, into a huge specially constructed container and out to a drain in the Garth (the cloisters central garden). Look carefully at the floor and you can still see the marks of adhesive tape that held the container in place. Written in Blood The wall by Dark Entry is where panelling, made in the studio to look just like the stone walling, was hung with the chilling message in blood really a film-makers magic potion that read: The Chamber of Secrets has been opened enemies of the heir BEWARE! The Poltergeists Cut In Harry Potter and the Philosophers Stone, Rik Mayall, as playful poltergiest Peeves, set all the broomsticks zooming about in the East Cloister walk. Unfortunately the scene was one of several that ended up on the cutting room floor because the film had to be cut to a manageable length. Troll Terror in the Lavatorium  | | Harry and Ron hid in the Lavatorium |
The Lavatorium on the left hand side of the North walk (yes, its really called that and it wasnt the ancient Abbey monks loo but the place they washed) is where Harry and Ron hide from a giant troll behind the pillars. The troll in the film is mainly computer-generated, but huge legs were used in filming to make it look more realistic so big that there was some difficulty in getting them in through the cathedrals massive main doors! Harry by Gaslight For filming the cloister walks were lit by special
gas-fired torches using a special gas that would not harm the ancient stonework. The Gryffindor Door As you come to the end of the West Walk the
oddly-named West Slype door is on your right. A slype is the name for a covered passage from a church or monastery cloister.  | | The West Slype doorway |
In the films it was made to look smaller by means of a plastic mould placed over the
real doorway, with a hinged portrait of the Fat Lady in front of it, and became the entrance to the Gryffindor Common Room. In real life steps lead down from the other side of the doorway but more film wizardry was used to make it look like the common room. A false floor on stilts was built sloping slightly
upwards to a backlit screen with a picture of the common room a film-making device called a translight. Click on the links below to take our virtual Harry Potter tour and see even more of Gloucester's Hogwart's! 
Find out more about Gloucester Cathedral and the kids who starred with Harry Potter. Also see our dramatic 360° panoramic pictures of the cathedral's magnificent interior. 
If you would like to comment on this or any other story on BBC Gloucestershire get in touch at gloucestershire@bbc.co.uk | 
Gloucestershire has probably the closest links of any county with the Harry Potter phenomenon.
