Severus Snape's office

The office used by Severus Snape during his long tenure as Potions master at Hogwarts School of Witchcraft and Wizardry was a gloomy and dimly-lit room found in the school dungeons. The shadowy walls were lined with shelves of large glass jars filled with slimy, revolting things, such as bits of animals and plants, floating in potions of varying colours. Snape's collection grew over time - in 1994 Harry Potter noted there were more jars than in 1992, and by 1996, there were hundreds of them. The office had a fireplace. In a corner, there was a cupboard containing Snape's private stock of Potions ingredients. In 1997, the office also contained a table, but it is unknown if it had been there before.

The office is sealed with a spell only wizards can break

1992
Harry Potter and Ron Weasley first entered Snape's office on September 1, 1992. Snape led them there after he caught them when they had flown the Flying Ford Anglia to Hogwarts. They were chilled when they reached the room, and the fireplace was cold and empty. Because he was not authorised to punish them, he then left them there and fetched Professor McGonagall, who lit a fire and asked them to explain. Dumbledore joined them and decided not to expel the boys. However, Ron and Harry were not allowed to return to the feast and had pumpkin juice and sandwiches that McGonagall summoned in Snape's office before they went to bed.

Hermione Granger stole bicorn horn and boomslang skin from Snape's office' in 1992 for the Polyjuice Potion. She slipped out of a Potions class while Harry diverted Snape.