The One Thing About "Downton Abbey" You've Never Noticed Before

    Or: WHAT IS IN THE TOWER?!?

    For five seasons now, audiences worldwide have been captivated by Downton Abbey — and the stunning estate that it calls home.

    That estate is really called Highclere Castle, and most of the show's "upstairs" interiors, as well as its exteriors, are shot on the location.

    There is one aspect of Downton/Highclere, however, that I have wondered about.

    Something that has, at times, piqued my curiosity.

    OK, often driven me to distraction.

    OK, become something of a preoccupation.

    OK, OK, become an all-consuming obsession.

    I know, I know, you think this is ridiculous.

    So imagine how ridiculous I felt when I discovered that we learned what was in the tower in the first episode of the entire show?

    It's in a quick scene between young footman William (Thomas Howes) and head housekeeper Mrs. Hughes (Phyllis Logan).

    William is storing some luggage, and Mrs. Hughes is mothering him as only Mrs. Hughes can.

    Did you catch that?

    That non-descript luggage room is apparently what is in the main tower at Highclere.

    Downton Abbey production designer Donal Woods explained to BuzzFeed News how they came to shoot in the tower — and why they'll likely never be back again.

    SPOILER ALERT: An earlier version of this story wondered how the dog on "Downton Abbey" was still alive, but, alas, the dog perished on Sunday's episode.