At the top of the stair
The Observatory
At the top of the tower: a telescope, a window, and a lantern. The emotional centre of the whole school.
Up the spiral stair, at the very top, is the observatory, with its great brass telescope trained on the Kentish sky, and the window, and the lantern that has burned in it every night for a hundred and fifty years. On a clear evening you may climb up, and look through the telescope, and understand rather more about the school than you did at the bottom of the stair.