Serpentine Corridor

The Serpentine Corridor is a passage on the third-floor of the Hogwarts Turris Magnus, connected to the courtyard corridor by a stairway and the first-floor corridor by another. Along the corridor are Classroom 3C, Classroom 7A, Lost Wands, and the Ghoul Studies classroom. Around the corner from Classroom 3C is a corridor where the staffroom sometimes exists.

1993-1994 School Year
Remus Lupin took his third year class out of Classroom 3C and along the corridor, where he had a confrontation with Peeves. After using Waddiwasi to send him away, they left for the staffroom.

2018-2019 School Year
Bartemius Crouch Junior was defeated in this corridor, and then was escorted further down where he was killed.