As a simple example - lets say that someone casts the Fidelius charm on a public building like Hogwarts or the Ministry of Magic.

Will everyone (so LOTS of people) immediately "forget" where these buildings are?

  • 5
    I think so - otherwise there wouldn't be much of a point in it.
    – Pwassonne
    Apr 12, 2016 at 12:20
  • 8
    Also think so... For instance Grimmauld Place : some DeathEaters probably knew the place or used to went there (since the son of the house was one of them), especially those related to the family (Bellatrix, Lucius...) - and then, once the Charm is cast, they cannot go there anymore - they might remember it's "somewhere in this area", but they can't find it
    – LilyM
    Apr 12, 2016 at 12:37
  • 3
    Although I would've thought that those buildings in particular would've had charms placed on them preventing people from using the Fidelius Charm on them. Otherwise one or two individuals would be able to highjack buildings that were essentially public property. Apr 19, 2016 at 22:15

2 Answers 2


While not stating it straight out, it appears that you can remember where-about the house was, but you'll not be able to locate it anymore.

Professor Flitwick cleared his throat.

‘An immensely complex spell,’ he said squeakily, ‘involving the magical concealment of a secret inside a single, living soul. The information is hidden inside the chosen person, or Secret-Keeper, and is henceforth impossible to find – unless, of course, the Secret- Keeper chooses to divulge it. As long as the Secret-Keeper refused to speak, You-Know-Who could search the village where Lily and James were staying for years and never find them, not even if he had his nose pressed against their sitting-room window!’ - Prisoner of Azkaban

This is implied that should Voldemort know that James and Lily lived in Godrics Hollow, it would still be impossible to locate their house, because of the magic that protects it.

Even later in the series we have Death Eaters/others hanging out in front of the Grimmauld Place, because they know where it's supposed to be, but can't see it.

Barely a day passed without one or two people arriving in Grimmauld Place with no other purpose, or so it seemed, than to lean against the railings facing numbers eleven and thirteen, watching the join between the two houses. The lurkers were never the same two days running, although they all seemed to share a dislike for normal clothing. -Deathly Hollows

Since knowing the location is possible, it's unlikely the spell would cause you to forget it.

  • 2
    @TylerH my guess is it would depend on whether he blew up each house individually (would 'somehow' miss theirs) or nuked Godric's Hollow from orbit, just to be sure (the destruction doesn't rely on finding their house) Apr 12, 2016 at 17:01
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    @TylerH he would never SEE their house, like harrys first visit to grimmauld place, he saw 11, and 13, right next to each, after reading the secret the house expanded and physically pushed the other 2 houses out of the way. so Voldemort would not have anything to destroy. it effectively doesn't exist for you until you know the secret, because magic.
    – Himarm
    Apr 12, 2016 at 17:03
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    @Himarm Well, in the case of Grimmauld Place, "every protection imaginable" had been placed on the location since it was the headquarters of the Order. So I wonder if that "animation" was only because of the Fidelius Charm or if it was the result of some other hidden protection (think Disillusionment Charm on a person)... it seemed to me like the process by which the house appeared was due to something else... a Fidelius Charm seems like you'd look, see 11 - 13, then be told about 12, then look again, and bam, in the blink of an eye 12 has appeared.
    – TylerH
    Apr 12, 2016 at 17:56
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    "Harry thought, and no sooner had he reached the part about number twelve, Grimmauld Place, than a battered door emerged out of nowhere between numbers eleven and thirteen, followed swiftly by dirty walls and grimy windows. It was as though an extra house had inflated, pushing those on either side out of its way." - order of the phoenix
    – Himarm
    Apr 12, 2016 at 17:58
  • 1
    @TylerH I actually asked that question: scifi.stackexchange.com/questions/104103/…
    – Adamant
    Apr 12, 2016 at 23:56


From Pottermore:

The Fidelius Charm is extremely ancient and still used to this day. It involves the concealment of information inside a living person. The chosen person, or Secret Keeper, is the only person who is thenceforth capable of revealing the protected information to others, however many previously knew it.
(Pottermore, "Secret Keeper").

This is in keeping with Himarm's answer. It seems that the Fidelius Charm induces forgetfulness about the specific location that's being protected. You'd forget where a location was and be unable to find it, even if you were very familiar with it. As Pwassonne says, there wouldn't be much point in it otherwise.

  • Does that line actually imply that those who knew will no longer know? Maybe it just means that they will no longer be able to reveal it to anyone.
    – Alex
    Dec 7, 2018 at 5:40
  • @Alex I believe so. I think it's saying that no matter how many people knew the location previously no-one will know it after the spell is cast other than the Secret-Keeper and those who they've told. A Fidelius Charm would be basically worthless, otherwise. Dec 7, 2018 at 18:23

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