https://www.independent.co.uk/arts-entertainment/books/news/loft-that-inspired-jane-eyre-s-madwoman-in-the-attic-open-for-public-tours-9661503.html 

This location inspired Novelist, Charlotte Brontë, in her contribution to the madwoman trope. Upon visiting the manor in 1839, Brontë encountered many elements that she incorporated into Jane Eyre eight years later. One of them being a legend of mad woman who had been confined in a remote attic room in the manor. This attic is known as “Mad Mary’s Room”, and is open to tourist today. Mad Mary constituted the creation of Bertha, and many features from Norton Conyers resemble the details of Mr Rochester’s house, “Thornfield Hall”. In 2004, a hidden staircase was discovered by staff that closely resembled the one Rochester uses to reach his wife’s attic.