The Chamber of Secrets is an underground chamber in Hogwarts built by Salazar Slytherin. It was guarded by snakes and parseltongue speakers.
- Tom Riddle: In 1942-1943 he released the Basilisk onto Muggle-Borns and killed Moaning Myrtle.
- Ginny Weasley/Tom Riddle: In 1993 Tom possessed Ginny to lead her into one of Tom's Horcruxes. Ginny gets trapped in the chamber and as Ginny grew weaker, Tom grew stronger
- Harry Potter, Ron Weasley and Gilderoy Lockhart: In 1993 they went to rescue Ginny, Ron and Lockhart got trapped so Harry had to go on
- Ron Weasley and Hermione Granger: In 1998 they went to aquire Basilisk fangs.