where they have Astronomy class every Wednesday night at midnight. Handy for meeting with broomstick riders in the dead of night - except when it requires hauling a heavy crate up the three flights of stairs from the Entrance Hall to the corridor beneath the tower. The top of this tower where observation sessions are held for Astronomy is more or less directly above the front entrance of the castle; the top of the tower has a parapet
A steep spiral staircase leads to the top of the tower, with a door (which has an iron ring as a handle) leading out onto the ramparts, which are crenelated. To get from the foot of the Astronomy Tower's staircase to the staircase leading to the entrance hall, one must pass through two corridors before rounding the corner to see the staircase leading (eventually) to the Entrance Hall