The Chamber of Secrets was created under the dungeons of Hogwarts School of Witchcraft and Wizardry during Medieval times bySalazar Slytherin, who disagreed with the other Hogwarts founders on the merits of blood purity. The Chamber of Secrets was home to an ancient Basilisk, which, according to legend, was intended to be used to purge the area of Muggle-born students. The Chamber is flanked with towering pillars entwined with carved wood, and a tall statue of Salazar Slytherin is at the far end. The basilisk rests within the mouth of the statue, possibly symbolising Salazar Slytherin's ability to speak Parseltongue. Sometime before 1992, the chamber flooded with water

On 2 May, 1998, during the Battle of Hogwarts, Ron Weasley andHermione Granger went back to the Chamber of Secrets to retrieve more fangs, since they needed  Basilisk venom  to destroy Voldemort's Horcruxes.

Ron was able to open the Chamber by mimicking the Parseltonguehe had heard Harry use to open Salazar Slytherin's Locket. Once inside, Hermione stabbed Helga Hufflepuff's Cup with a Basilisk fang taken from the dead Basilisk's skeleton, destroying the Horcrux.