Which Hogwarts founder created the Chamber of Secrets in J.K. Rowling’s series?

Salazar Slytherin created the Chamber of Secrets in J.K. Rowling’s Harry Potter series. He was one of Hogwarts’ four founders and built the hidden chamber beneath the school before leaving after disagreements with the other founders.

According to the school’s legend, Slytherin believed that only students with magical ancestry should attend Hogwarts. The chamber was concealed so that his heir could eventually open it and release a monster capable of attacking students he considered unworthy. The creature inside is a basilisk.

The chamber becomes the central mystery of Harry Potter and the Chamber of Secrets. Tom Riddle, later known as Lord Voldemort, opens it during his time as a student, and it is opened again in Harry’s second year. Salazar Slytherin should not be confused with the chamber’s monster: he built the chamber, while the basilisk occupies it.