Professor Snape's office

Below the ground floor of Hogwarts are several dungeons. The dungeons are the location for Professor Snape’s office, which was a gloomy room with low light and was “lined with shelves of glass jars” filled with dreadful things. In one corner was a cupboard which contained Snape’s private stock of potion ingredients—a cupboard which was frequently plundered by various characters from the series.