You may watch this holiday comedy every year without knowing parts of it were filmed in a Colorado middle school, and even a Walmart. (That's right... a Walmart.)

Last year, Shannon Ogden on Denver7 did a report on holiday movies you didn't know were shot in Colorado, and while most of them, admittedly, were duds, there is one that certainly was not — National Lampoon's Christmas Vacation, starring Chevy Chase.

As some have pointed out, the film is set in the Midwest, which is funny because the Midwest doesn't have mountains. Despite that, the part of the movie where the Griswolds are Christmas tree shopping was actually (clearly) shot in Breckenridge. Additionally, the home set was on a Warner lot in Hollywood, so you never see anyone's breath when they are out in the snow, as Mental Floss notes.

Check out all the local filming locations via Denver7: