The Chamber of Secrets

• Type: Legendary Hidden Chamber
• Location: Deep beneath the dungeons of Hogwarts School of Witchcraft and Wizardry, Scotland
• Owner/Residents: Created by Salazar Slytherin. Its primary resident was his Basilisk. It was later controlled by the Heir of Slytherin, Tom Marvolo Riddle.
• Key Features: Concealed entrance requiring Parseltongue to open; home to a deadly Basilisk; large, carved stone pillars; a colossal statue of Salazar Slytherin.

The Chamber of Secrets is a legendary secret room constructed by Salazar Slytherin, one of the four Hogwarts Founders, without the knowledge of his colleagues Godric Gryffindor, Rowena Ravenclaw, and Helga Hufflepuff. The chamber's creation stemmed from a fundamental disagreement over student admissions; Slytherin believed that magical education should be reserved for those of pure-blood lineage only, excluding Muggle-born students. When his views were rejected, he left the school, but not before secretly building the Chamber. According to legend, Slytherin sealed a monster within the Chamber—a Basilisk—that only his own true Heir of Slytherin could control. The purpose of the Chamber and its monster was to one day purge the school of all who were, in Slytherin's view, unworthy to study magic. For centuries, the Chamber was considered a mere myth. The entrance is located in the second-floor girls' lavatory, the one haunted by Myrtle Warren (Moaning Myrtle). One of the copper taps, which has never worked, is marked with a tiny, scratched snake. Speaking the Parseltongue word for “Open” causes the sink to vanish, revealing a large, dark pipe. This pipe is a slide that leads into a series of stone tunnels far below the school, littered with the skeletons of small animals. The main tunnel terminates at a solid wall, upon which two intertwining stone serpents are carved. Again, Parseltongue is required to make the wall open into the Chamber proper. The Chamber itself is a long, high room filled with a greenish, dim light. Tall stone pillars carved with more serpents rise to a ceiling lost in darkness. At the far end of the Chamber stands a colossal, ancient-looking statue of Salazar Slytherin, which serves as the lair for the Basilisk.

The Chamber is central to the plot of Harry Potter and the Chamber of Secrets and plays a significant role in the final book.

• First Opening (1942-1943): A sixteen-year-old Tom Marvolo Riddle discovered and opened the Chamber. He used the Basilisk to attack students, resulting in the death of Myrtle Warren in the lavatory. When Headmaster Armando Dippet threatened to close the school, Riddle framed Rubeus Hagrid and his Acromantula, Aragog, for the attacks. Riddle preserved a memory of himself in a magical diary to ensure the Chamber could one day be reopened.
• Second Opening (1992-1993): Lucius Malfoy slipped Tom Riddle's Diary into Ginny Weasley's cauldron of schoolbooks. Under the diary's influence, Ginny was forced to reopen the Chamber. The Basilisk was unleashed once more, petrifying several victims: Mrs Norris, Colin Creevey, Justin Finch-Fletchley, Penelope Clearwater, and Hermione Granger. Harry Potter, upon discovering the entrance with Ron Weasley, entered the Chamber to rescue Ginny. There, he confronted the memory of Tom Riddle. With the help of Fawkes the Phoenix, who brought him the Sorting Hat containing the Sword of Godric Gryffindor, Harry slew the Basilisk. He then used a Basilisk Fang to stab the diary, destroying the Horcrux within and vanquishing Riddle's memory.
• Battle of Hogwarts (1998): During the climax of the Second Wizarding War, Ron Weasley and Hermione Granger returned to the Chamber. Ron managed to open the entrance by mimicking the Parseltongue sounds he had heard Harry make. They retrieved Basilisk Fangs from the great serpent's skeleton, which Hermione then used to destroy another of Lord Voldemort's Horcruxes: Helga Hufflepuff's Cup.

• The Entrance: A specific tap on a sink in the second-floor girls' lavatory, also known as Moaning Myrtle's bathroom.
• The Slide: A large, dark pipe leading down from the bathroom entrance deep into the castle's foundations.
• The Tunnel Network: A series of dark, stone-flagged corridors beneath the school, littered with the bones of the Basilisk's prey.
• The Antechamber Door: A solid wall at the end of a long tunnel, featuring two carved, interlocking serpents that move apart when commanded in Parseltongue.
• The Main Chamber: The vast, primary chamber containing the great statue of Salazar Slytherin from whose mouth the Basilisk emerges.

• In the film adaptation of *Harry Potter and the Chamber of Secrets*, the entrance to the Chamber is depicted as a ring of sinks in the center of the lavatory, with the snake symbol on one of the taps. The main chamber set was a significant piece of production design, featuring immense snake-headed pillars and a giant sculpt of Slytherin's head.
• J.K. Rowling revealed on Pottermore that the legend of the Chamber was kept alive for centuries because Slytherin's descendants, and those they told, spoke of it. The lack of discovery was partly due to the fact that until plumbing was installed at Hogwarts in the eighteenth century, the entrance was hidden behind a concealed trapdoor and a series of magical tunnels. The installation of plumbing by a student named Corvinus Gaunt, a direct descendant of Slytherin, allowed the entrance to be incorporated into the new lavatory, protecting it from being discovered. (Pottermore)