"Let's see ... ah, yes, this is nice and cosy." -- Rita Skeeter
A broom cupboard is located off the Entrance Hall. Harry and Ron locked Crabbe and Goyle in it (CS12); Hermione and Harry hid here while using the Time-Turner to wait for themselves to pass through the Entrance Hall (PA21). Rita Skeeter interviewed Harry in this cupboard during the weighing of the wands ceremony (GF18).
"[Rita Skeeter] was steering him out of the room again, and opening a nearby door. [...] 'this is nice and cosy.' It was a broom cupboard. Harry stared at her" (GF18).
"perching herself precariously upon an upturned bucket, pushing Harry down onto a cardboard box" (GF18).