The rickety old door that previously would not budge no matter who tried to open it for nearly a century has suddenly become a bit more accommodating.

Upon first glance, the interior of the room resembles nothing more than a disused bathroom covered in dust and cobwebs but with orange boxes embellished with a large 'W' thrown about the place haphazardly. The contents of these boxes, while very old, are still potent and functioning. So be careful opening them and inspecting their contents. You may just set off a dungbomb or Weasleys' Wildfire Whiz-bangs. Perhaps you'll get lucky and find some Extendable Ears or a Screaming Yo-yo or something else entirely.

A crawlspace in one of the abandoned stalls will lead you to the Gryffindor Tower Reading Room. You'll just need to stand on the toilet to reach it.